Please commit your Livebook to GitHub!

I made a PR to add .livemd extension to GitHub linguist.

https://github.com/github/linguist/pull/5672

But it’s pending now because of its less popularity on GitHub.
I love Livebook, so want to introduce it to many people.
If .livemd can be rendered as Markdown on GitHub, many people will fill Livebook more friendly.

Thanks!