Chore/contributing.md (#2003)

* chore: add base CONTRIBUTING.md file

* chore: mark git hook for message convention optional

* chore: add info about issue number

* fix: text formatting

* chore: clarify intro message

CONTRIBUTING.md

@@ -0,0 +1,50 @@
+# Contributing
+
+## Development workflow
+
+> **New to open source?** You can learn how from this _free_ series: [How to Contribute to an Open Source Project on GitHub](https://egghead.io/courses/how-to-contribute-to-an-open-source-project-on-github).
+
+1. Fork the repo and create your branch from `develop` (a guide on [how to fork a repository](https://help.github.com/articles/fork-a-repo/)).
+2. Being in the root directory, run `npm i` and then `lerna bootstrap`, to setup the development environment.
+3. Check out [desktop](https://github.com/TryQuiet/quiet/blob/develop/packages/desktop/README.md) and [mobile](https://github.com/TryQuiet/quiet/blob/develop/packages/mobile/README.md) README.md for more instructions.
+
+## Commit message convention
+
+Prefix commit messages with one of the following to signify the kind of change:
+
+- `fix:` bug fixes, e.g. fix incorrect error message.
+- `feat:` new features, e.g. add useful API.
+- `refactor:` code/structure refactor, e.g. new folder structure.
+- `docs:` changes into documentation, e.g. add usage example for getByText.
+- `test:` adding or updating tests, eg unit, snapshot testing.
+- `chore:` tooling changes, e.g. change circle ci config.
+- `BREAKING:` for changes that break existing usage, e.g. change API.
+
+Commit message should be followed by the issue number, eg.
+`fix: typo #2002`
+
+### (optional) Setting up a local git hook for verifying message convention:
+
+1. Navigate to git repository in your terminal.
+2. Go to the .git/hooks directory:
+```
+cd .git/hooks
+```
+3. Create (or edit if it already exists) the commit-msg file
+4. Make the file executable:
+```
+chmod +x commit-msg
+```
+5. Edit the commit-msg file and paste the following shell script:
+```
+#!/bin/bash
+
+COMMIT_MSG_FILE=$1
+COMMIT_MSG=$(cat $COMMIT_MSG_FILE)
+
+if ! echo "$COMMIT_MSG" | grep -E '^(fix:|feat:|refactor:|docs:|test:|chore:|BREAKING:|Publish)' > /dev/null; then
+    echo "error: invalid commit message format"
+    echo "Valid formats are fix: feat: refactor: docs: test: chore: BREAKING:"
+    exit 1
+fi
+```