docs(contributing): add Contributing TL;DR page

Author: bearomorphism

docs/contributing_tldr.md

@@ -0,0 +1,28 @@
+Feel free to send a PR to update this file if you find anything useful. 🙇
+
+## Environment
+
+- Python `>=3.9`
+- [Poetry](https://python-poetry.org/docs/#installing-with-the-official-installer) `>=2.0.0`
+
+## Useful commands
+
+Please check the [pyproject.toml](https://github.com/commitizen-tools/commitizen/blob/master/pyproject.toml) for a comprehensive list of commands.
+
+```bash
+# Ensure you have the correct dependencies
+poetry install
+
+# Make ruff happy
+poetry format
+
+# Check if ruff and mypy are happy
+poetry lint
+
+# Check if mypy is happy in python 3.9
+mypy --python-version 3.9
+
+# Run tests in parallel.
+pytest -n auto # This may take a while.
+pytest -n auto <test_suite>
+```

mkdocs.yml

@@ -58,6 +58,7 @@ nav:
   - Exit Codes: "exit_codes.md"
   - Third-Party Commitizen Templates: "third-party-commitizen.md"
   - Contributing: "contributing.md"
+  - Contributing TL;DR: "contributing_tldr.md"
   - Resources: "external_links.md"
 
 markdown_extensions: