RE: I Dunno... but I made a GitHub Repo

How to write a proper README.md

Markdown syntax is largely the same as posts on Hive. Usually this will describe what it does, how to compile/run and configure it.

How to create or respond to Issues

Looks like you just created one. You may want to include crash logs in your issue. Close them when the issue has been resolved.

How others contribute to my code or suggest changes

They will make a fork of your repo, make their changes in a branch and submit a pull request for you to review and merge.

How to keep everything synced when I'm editing locally vs online

git pull to fetch remote changes or git push to push any changes made locally. I personally use Github desktop to manage my repos.