docs: Create PR template (no-changelog) (#7902)

## Summary
Provide details about your pull request and what it adds, fixes, or
changes. Photos and videos are recommended.
Add PR template

#### How to test the change:
1. Create new PR.


## Issues fixed
Include links to Github issue or Community forum post or **Linear
ticket**:
> Important in order to close automatically and provide context to
reviewers

[ADO-1200](https://linear.app/n8n/issue/ADO-1200/tech-debt-checklist)


## Review / Merge checklist
- [X] PR title and summary are descriptive. **Remember, the title
automatically goes into the changelog. Use `(no-changelog)` otherwise.**
([convetions](./blob/master/pull_request_title_conventions.md))
- [ ] [Docs updated](https://github.com/n8n-io/n8n-docs) or follow-up
ticket created.
- [ ] Tests included.
   > A feature is not complete without tests. 
> A bug is not considered fixed, unless a test is added to prevent it
from happening again.
   >
> *(internal)* You can use Slack commands to trigger [e2e
tests](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#a39f9e5ba64a48b58a71d81c837e8227)
or [deploy test
instance](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#f6a177d32bde4b57ae2da0b8e454bfce)
or [deploy early access version on
Cloud](https://www.notion.so/n8n/Cloudbot-3dbe779836004972b7057bc989526998?pvs=4#fef2d36ab02247e1a0f65a74f6fb534e).

.github/pull_request_template.md

@@ -1 +1,23 @@
-Github issue / Community forum post (link here to close automatically):
+## Summary
+Provide details about your pull request and what it adds, fixes, or changes. Photos and videos are recommended.
+
+...
+
+#### How to test the change:
+1. ...
+
+
+## Issues fixed
+Include links to Github issue or Community forum post or **Linear ticket**:
+> Important in order to close automatically and provide context to reviewers
+
+...
+
+
+## Review / Merge checklist
+- [ ] PR title and summary are descriptive. **Remember, the title automatically goes into the changelog. Use `(no-changelog)` otherwise.** ([conventions](https://github.com/n8n-io/n8n/blob/master/.github/pull_request_title_conventions.md))
+- [ ] [Docs updated](https://github.com/n8n-io/n8n-docs) or follow-up ticket created.
+- [ ] Tests included.
+   > A bug is not considered fixed, unless a test is added to prevent it from happening again. A feature is not complete without tests. 
+  >
+  > *(internal)* You can use Slack commands to trigger [e2e tests](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#a39f9e5ba64a48b58a71d81c837e8227) or [deploy test instance](https://www.notion.so/n8n/How-to-use-Test-Instances-d65f49dfc51f441ea44367fb6f67eb0a?pvs=4#f6a177d32bde4b57ae2da0b8e454bfce) or [deploy early access version on Cloud](https://www.notion.so/n8n/Cloudbot-3dbe779836004972b7057bc989526998?pvs=4#fef2d36ab02247e1a0f65a74f6fb534e).

.github/pull_request_title_conventions.md

@@ -0,0 +1,112 @@
+# PR Title Convention
+
+We have very precise rules over how Pull Requests (to the `master` branch) must be formatted. This format basically follows the [Angular Commit Message Convention](https://github.com/angular/angular/blob/master/CONTRIBUTING.md#commit). It leads to easier to read commit history and allows for automated generation of release notes:
+
+A PR title consists of these elements:
+
+```
+<type>(<scope>): <summary>
+  │       │          │
+  │       │          └─⫸ Summary: In imperative present tense.
+  |       |                        Capitalized
+  |       |                        No period at the end.
+  │       │
+  │       └─⫸ Scope: API|core|editor|* Node
+  │
+  └─⫸ Type: build|ci|docs|feat|fix|perf|refactor|test
+```
+
+- PR title
+    - type
+    - scope (*optional*)
+    - summary
+- PR description
+    - body (optional)
+    - blank line
+    - footer (optional)
+
+The structure looks like this:
+
+### **Type**
+
+Must be one of the following:
+
+- `feat` - A new feature
+- `fix` - A bug fix
+- `perf` - A code change that improves performance
+- `test` - Adding missing tests or correcting existing tests
+- `docs` - Documentation only changes
+- `refactor` - A code change that neither fixes a bug nor adds a feature
+- `build` - Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
+- `ci` - Changes to our CI configuration files and scripts (e.g. Github actions)
+
+If the prefix is `feat`, `fix` or `perf`, it will appear in the changelog. However if there is any BREAKING CHANGE (see Footer section below), the commit will always appear in the changelog.
+
+### **Scope (optional)**
+
+The scope should specify the place of the commit change as long as the commit clearly addresses one of the following supported scopes. (Otherwise, omit the scope!)
+
+- `API` - changes to the *public* API
+- `core` - changes to the core / private API / backend of n8n
+- `editor` - changes to the Editor UI
+- `* Node` - changes to a specific node or trigger node (”`*`” to be replaced with the node name, not its display name), e.g.
+    - mattermost → Mattermost Node
+    - microsoftToDo  → Microsoft To Do Node
+    - n8n → n8n Node
+
+### **Summary**
+
+The summary contains succinct description of the change:
+
+- use the imperative, present tense: "change" not "changed" nor "changes"
+- capitalize the first letter
+- *no* dot (.) at the end
+- do *not* include Linear ticket IDs etc. (e.g. N8N-1234)
+- suffix with “(no-changelog)” for commits / PRs that should not get mentioned in the changelog.
+
+### **Body (optional)**
+
+Just as in the **summary**, use the imperative, present tense: "change" not "changed" nor "changes". The body should include the motivation for the change and contrast this with previous behavior.
+
+### **Footer (optional)**
+
+The footer can contain information about breaking changes and deprecations and is also the place to [reference GitHub issues](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword), Linear tickets, and other PRs that this commit closes or is related to. For example:
+
+```
+BREAKING CHANGE: <breaking change summary>
+<BLANK LINE>
+<breaking change description + migration instructions>
+<BLANK LINE>
+<BLANK LINE>
+Fixes #<issue number>
+```
+
+or
+
+```
+DEPRECATED: <what is deprecated>
+<BLANK LINE>
+<deprecation description + recommended update path>
+<BLANK LINE>
+<BLANK LINE>
+Closes #<pr number>
+```
+
+A Breaking Change section should start with the phrase "`BREAKING CHANGE:` " followed by a summary of the breaking change, a blank line, and a detailed description of the breaking change that also includes migration instructions.
+
+> 💡 A breaking change can additionally also be marked by adding a “`!`” to the header, right before the “`:`”, e.g. `feat(editor)!: Remove support for dark mode`
+> 
+> This makes locating breaking changes easier when just skimming through commit messages.
+
+> 💡 The breaking changes must also be added to the [packages/cli/BREAKING-CHANGES.md](https://github.com/n8n-io/n8n/blob/master/packages/cli/BREAKING-CHANGES.md) file located in the n8n repository.
+
+Similarly, a Deprecation section should start with "`DEPRECATED:` " followed by a short description of what is deprecated, a blank line, and a detailed description of the deprecation that also mentions the recommended update path.
+
+### **Revert commits**
+
+If the commit reverts a previous commit, it should begin with `revert:` , followed by the header of the reverted commit.
+
+The content of the commit message body should contain:
+
+- information about the SHA of the commit being reverted in the following format: `This reverts commit <SHA>`,
+- a clear description of the reason for reverting the commit message.