You found a bug, or a fix for a bug? Here's how to tell devs!
For players (reporting bugs)Edit
Go to the issues page on the official Github, and select the new issue button, then label it something like [BUG] <insert bug name here> so I'll see it. Describe the bug and how to reproduce it, not just "my client broke haaalp", because that doesn't do me any good.
Later, once one of the contribs notices your issue the proper tags will be assigned and the annoying [BUG] on the front will be removed.
For modders (with bugfixes)Edit
Fork the project (if you haven't already) and put your changes on your fork, then submit a pull request to the official repo, for hopefully merging stuff from your fork into the official. If it looks like it'll be easy to merge, we'll merge your changes into the official repo (and give credit where it's due) and all will be well!