README: Add contributing section

README.md

@@ -72,5 +72,26 @@ pdfposter -s1 score.pdf print.pdf
  - [Frequency to Musical Note Converter](https://newt.phys.unsw.edu.au/music/note/)
 
 
+
+## Contributing
+Contributions are very welcome - both bug reports and code contributions! Bug reports can be made to my email address (available on my website <https://starbeamrainbowlabs.com/>). Code contributions can be sent as a patch via email. Do this to generate a patch file you can attach to an email:
+
+```bash
+git format-patch --stdout origin > patch_file.patch
+```
+
+This generates a patch file for all unpushed commits. To specify a specific commit range, do this:
+
+```bash
+git format-patch --stdout FIRST_COMMIT..LAST_COMMIT > patch_file.patch
+```
+
+Please mention in at least 1 commit message that you release your all your work under the MPL-2.0 (see below), as otherwise I will be unable to accept it (work you produce is as far as I know automatically copyright, so unless you release it under a licence no matter how awesome it is I'm not allowed to use it).
+
+If there's significant interest in this, I can move it to [my GitHub account](https://github.com/sbrl) to make collaboration easier.
+
+If you're feeling that way inclined I have a [Liberapay profile](https://liberapay.com/sbrl) if you'd like to donate to say an extra thank you :-)
+
+
 ## License
 This project is released under the Mozilla Public License 2.0. The full license text is included in the `LICENSE` file in this repository. Tldr legal have a [great summary](https://tldrlegal.com/license/mozilla-public-license-2.0-(mpl-2)) of the license if you're interested.