docs: add package alias info

docs/content/cli-commands/npm-install.md

@@ -16,6 +16,7 @@ npm install [<@scope>/]<name>
 npm install [<@scope>/]<name>@<tag>
 npm install [<@scope>/]<name>@<version>
 npm install [<@scope>/]<name>@<version range>
+npm install <alias>@npm:<name>
 npm install <git-host>:<git-user>/<repo-name>
 npm install <git repo url>
 npm install <tarball file>
@@ -63,8 +64,7 @@ after packing it up into a tarball (b).
     With the `--production` flag (or when the `NODE_ENV` environment variable
     is set to `production`), npm will not install modules listed in
     `devDependencies`. To install all modules listed in both `dependencies` 
-    and `devDependencies` when `NODE_ENV` environment variable is set to `production`, 
-    you can use `--production=false`.
+    and `devDependencies` when `NODE_ENV` environment variable is set to `production`, you can use `--production=false`.
 
     > NOTE: The `--production` flag has no particular meaning when adding a
     dependency to a project.
@@ -78,13 +78,10 @@ after packing it up into a tarball (b).
 
 * `npm install <tarball file>`:
 
-    Install a package that is sitting on the filesystem.  Note: if you just want
-    to link a dev directory into your npm root, you can do this more easily by
-    using `npm link`.
+    Install a package that is sitting on the filesystem.  Note: if you just want to link a dev directory into your npm root, you can do this more easily by using `npm link`.
 
     Tarball requirements:
-    * The filename *must* use `.tar`, `.tar.gz`, or `.tgz` as
-    the extension.
+    * The filename *must* use `.tar`, `.tar.gz`, or `.tgz` as the extension.
     * The package contents should reside in a subfolder inside the tarball (usually it is called `package/`). npm strips one directory layer when installing the package (an equivalent of `tar x --strip-components=1` is run).
     * The package must contain a `package.json` file with `name` and `version` properties.
 
@@ -94,8 +91,7 @@ after packing it up into a tarball (b).
 
 * `npm install <tarball url>`:
 
-    Fetch the tarball url, and then install it.  In order to distinguish between
-    this and other options, the argument must start with "http://" or "https://"
+    Fetch the tarball url, and then install it.  In order to distinguish between this and other options, the argument must start with "http://" or "https://"
 
     Example:
 
@@ -113,12 +109,22 @@ after packing it up into a tarball (b).
 
           npm install sax
 
+* `npm install <alias>@npm:<name>`:
+
+    Install a package under a custom alias. Allows multiple versions of a same-name package side-by-side, more convenient import names for packages with otherwise long ones and using git forks replacements or forked npm packages as replacements. Aliasing works only on your project and does not rename packages in transitive dependencies. Aliases should follow the naming conventions stated in [`validate-npm-package-name`](https://www.npmjs.com/package/validate-npm-package-name#naming-rules).
+
+    Examples:
+
+          npm install my-react@npm:react
+          npm install jquery2@npm:jquery@2
+          npm install jquery3@npm:jquery@3
+          npm install npa@npm:npm-package-arg
+
     `npm install` saves any specified packages into `dependencies` by default.
     Additionally, you can control where and how they get saved with some
     additional flags:
 
-    * `-P, --save-prod`: Package will appear in your `dependencies`. This is the
-                         default unless `-D` or `-O` are present.
+    * `-P, --save-prod`: Package will appear in your `dependencies`. This is the default unless `-D` or `-O` are present.
 
     * `-D, --save-dev`: Package will appear in your `devDependencies`.
 
@@ -135,8 +141,7 @@ after packing it up into a tarball (b).
 
     * `-B, --save-bundle`: Saved dependencies will also be added to your `bundleDependencies` list.
 
-    Further, if you have an `npm-shrinkwrap.json` or `package-lock.json` then it
-    will be updated as well.
+    Further, if you have an `npm-shrinkwrap.json` or `package-lock.json` then it will be updated as well.
 
     `<scope>` is optional. The package will be downloaded from the registry
     associated with the specified scope. If no registry is associated with
@@ -189,8 +194,7 @@ after packing it up into a tarball (b).
 
 * `npm install [<@scope>/]<name>@<version range>`:
 
-    Install a version of the package matching the specified version range.  This
-    will follow the same rules for resolving dependencies described in [`package.json`](/configuring-npm/package-json).
+    Install a version of the package matching the specified version range.  This will follow the same rules for resolving dependencies described in [`package.json`](/configuring-npm/package-json).
 
     Note that most version ranges must be put in quotes so that your shell will
     treat it as a single argument.
@@ -216,8 +220,7 @@ after packing it up into a tarball (b).
     If `#<commit-ish>` is provided, it will be used to clone exactly that
     commit. If the commit-ish has the format `#semver:<semver>`, `<semver>` can
     be any valid semver range or exact version, and npm will look for any tags
-    or refs matching that range in the remote repository, much as it would for a
-    registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
+    or refs matching that range in the remote repository, much as it would for a registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
     specified, then the default branch of the repository is used.
 
     If the repository makes use of submodules, those submodules will be cloned
@@ -259,8 +262,7 @@ after packing it up into a tarball (b).
     If `#<commit-ish>` is provided, it will be used to clone exactly that
     commit. If the commit-ish has the format `#semver:<semver>`, `<semver>` can
     be any valid semver range or exact version, and npm will look for any tags
-    or refs matching that range in the remote repository, much as it would for a
-    registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
+    or refs matching that range in the remote repository, much as it would for a registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
     specified, then `master` is used.
 
     As with regular git dependencies, `dependencies` and `devDependencies` will
@@ -298,8 +300,7 @@ after packing it up into a tarball (b).
     If `#<commit-ish>` is provided, it will be used to clone exactly that
     commit. If the commit-ish has the format `#semver:<semver>`, `<semver>` can
     be any valid semver range or exact version, and npm will look for any tags
-    or refs matching that range in the remote repository, much as it would for a
-    registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
+    or refs matching that range in the remote repository, much as it would for a registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
     specified, then `master` is used.
 
     As with regular git dependencies, `dependencies` and `devDependencies` will
@@ -320,8 +321,7 @@ after packing it up into a tarball (b).
     If `#<commit-ish>` is provided, it will be used to clone exactly that
     commit. If the commit-ish has the format `#semver:<semver>`, `<semver>` can
     be any valid semver range or exact version, and npm will look for any tags
-    or refs matching that range in the remote repository, much as it would for a
-    registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
+    or refs matching that range in the remote repository, much as it would for a registry dependency. If neither `#<commit-ish>` or `#semver:<semver>` is
     specified, then `master` is used.
 
     As with regular git dependencies, `dependencies` and `devDependencies` will
@@ -352,16 +352,15 @@ have done without actually installing anything.
 The `--package-lock-only` argument will only update the `package-lock.json`,
 instead of checking `node_modules` and downloading dependencies.
 
-The `-f` or `--force` argument will force npm to fetch remote resources even if a
-local copy exists on disk.
+The `-f` or `--force` argument will force npm to fetch remote resources even if a local copy exists on disk.
 
 ```bash
 npm install sax --force
 ```
 
 The `--no-fund` argument will hide the message displayed at the end of each
 install that acknowledges the number of dependencies looking for funding.
-See `npm-fund(1)`
+See `[npm fund]`(/cli-commands/npm-fund).
 
 The `-g` or `--global` argument will cause npm to install the package globally
 rather than locally.  See [folders](/configuring-npm/folders).
@@ -402,7 +401,7 @@ The `--only={prod[uction]|dev[elopment]}` argument will cause either only
 `devDependencies` or only non-`devDependencies` to be installed regardless of the `NODE_ENV`.
 
 The `--no-audit` argument can be used to disable sending of audit reports to
-the configured registries.  See [`npm-audit`](npm-audit) for details on what is sent.
+the configured registries.  See [`npm audit`](/cli-commands/npm-audit) for details on what is sent.
 
 See [`config`](/using-npm/config).  Many of the configuration params have some
 effect on installation, since that's most of what npm does.

lib/install.js

@@ -26,6 +26,7 @@ install.usage = usage(
   '\nnpm install [<@scope>/]<pkg>@<tag>' +
   '\nnpm install [<@scope>/]<pkg>@<version>' +
   '\nnpm install [<@scope>/]<pkg>@<version range>' +
+  '\nnpm install <alias>@npm:<name>' +
   '\nnpm install <folder>' +
   '\nnpm install <tarball file>' +
   '\nnpm install <tarball url>' +