docs: Add CONTRIBUTING.md (#405)

Co-authored-by: erdaltsksn <erdal@taskesen.me>

CONTRIBUTING.md

@@ -0,0 +1,13 @@
+# Contributing
+
+Pull requests are welcome for any changes.
+
+Consider opening an issue for larger changes to get feedback on the idea from the team.
+
+If your change touches parts of the Bubble Tea renderer or internals, make sure
+that all the examples in the `examples/` folder continue to run correctly.
+
+For commit messages, please use conventional commits[^1] to make it easier to
+generate release notes.
+
+[^1]: https://www.conventionalcommits.org/en/v1.0.0