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CONTRIBUTING.md

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+## Contributing to river
+
+Contributing is a simple as opening a pull request on our github. You'll likely
+have find more success with your contribution if you hop on our
+[matrix channel](https://matrix.to/#/#river:matrix.org) to discuss your plans
+first.
+
+## Commit messages
+
+Please take the time to write a good commit message, having a clean git history
+makes maintaining and contributing to river easier. Commit messages should start
+with a summary in 50 characters or less. This summary should complete the
+sentence "When applied, this commit will...". 
+
+In addition to the summary, feel free to add any other details you want preceded
+by a blank line. A good rule of thumb is that anything you would write in a pull
+request description on github has a place in the commit message as well.
+
+For more discussion and details of good commit message practices, check out
+ihttps://chris.beams.io/posts/git-commit/
+
+## Coding style
+
+Please follow the
+[Zig Style Guide](the https://ziglang.org/documentation/master/#Style-Guide)
+and run `zig fmt` before every commit. With regards to line length, consider 100
+characters to be a hard upper limit and 80 or less to be the goal. Note that
+inserting a trailing comma after the last parameter in function calls, struct
+declarations, etc. will cause `zig fmt` to wrap those lines. I highly recommend
+configuring your editor to run `zig fmt` on write.
+
+On a higher level, prioritize simplicity of code over nearly everything else.
+Performance is only a valid reason for code complexity if there are profiling
+results to back it up which demonstrate a significant benefit.