For what it's worth, this is the problem GitLab Pages solves. A simple "git push" to a properly to figured repo will rebuild and redeploy your static site, the actual html output doesnt go into the repo.

This is for people who don't want to setup and manage a deployment pipeline hooked up to a git source code repo.

Sooo a live editor like this? http://www2.hyperfiddle.net/:markdown/ If you like that, here's a little tweetstorm about hyperfiddle markdown: https://twitter.com/dustingetz/status/1048686717975388160