docs: document branching (#9983)

* docs: document branching

Note: I'll tweak this, want to see if the CircleCI filter stuff works

* chore: dos2unix

docs/docs/how-to-contribute.md

@@ -50,6 +50,7 @@ Yarn is a package manager for your code, similar to [NPM](https://www.npmjs.com/
 - Set up repo and install dependencies: `yarn run bootstrap`
 - Make sure tests are passing for you: `yarn test`
 - Create a topic branch: `git checkout -b topics/new-feature-name`
+  - Note: if making a docs only change, consider using `git checkout -b docs/some-change` or `git checkout -b docs-some-change`, as this will short circuit the CI process and only run linting tasks
 - Run `yarn run watch` from the root of the repo to watch for changes to packages' source code and compile these changes on-the-fly as you work. Note that the watch command can be resource intensive. To limit it to the packages you're working on, add a scope flag, like `yarn run watch -- --scope={gatsby,gatsby-cli}`. To watch just one package, run `yarn run watch -- --scope=gatsby`.
 - Install [gatsby-dev-cli](/packages/gatsby-dev-cli/) globally: `yarn global add gatsby-dev-cli`
 - Run `yarn install` in each of the sites you're testing.
@@ -127,6 +128,7 @@ To add a new blog post to the gatsbyjs.org blog:
 - Double check your grammar and capitalise correctly
 - Commit and push to your fork
 - Create a pull request from your branch
+  - We recommend using a prefix of `docs`, e.g. `docs/your-change` or `docs-your-change`
 
 ## Development tools