Submission Statement: I found myself editing many README files in markdown, and I was making commits that were entirely just for fixing the README. When I looked for a Markdown editor, I couldn't find a live-edit version that was free, so I hacked this together. It probably has some bugs, but definitely works for me for what I was looking for.
Push CTRL+6 for the github repo. All data is stored locally.
Please let me know what you think!