Add note about backport and linting

Pull-Request-Checklist.md

@@ -87,4 +87,21 @@ For bug and security fixes, parallel pull requests must be sent to all [supporte
 
 For example, if you fix a bug in v11 (`hotfix` branch), then you must also cherry-pick the commit and send another pull request on the `develop` branch.
 
-Note: It is better to send backport pull request once your main pull request gets approved.
+If your fixes are small, you might not need a manual backport. Leave a note in your PR description or comment that PR can be squashed and backported to stable versions. Read more on automated backports here: https://github.com/frappe/backport#how-to-use
+
+Note: It is better to send backport pull requests once your main pull request gets approved.
+
+### Linting
+
+This repository uses https://pre-commit.com/ to ensure that basic code style and correctness requirements are met before merging any PRs. While the suite of linting/formatting tools might keep evolving you just need to install `pre-commit` to get started. It will install and configure required tools.  
+
+- `pip install pre-commit`
+- `pre-commit install` (from ERPNext repository folder)
+
+This will configure a git pre-commit hook which will ensure that your changes pass bare-minimum style/correctness requirements. 
+
+![pre-commit](https://user-images.githubusercontent.com/9079960/131657035-f43d6324-131a-4337-9cb0-587edba33e73.png)
+
+Current checks:
+- Flake8 (correctness)
+- Whitespace trimming (style)