the Node.js community seems to have many tools to juggle Markdown, some of them supporting CommonMark.
Yesterday I stumbled upon some tool using this one (I have no idea if it is good or fits exactly your needs): https://www.npmjs.com/package/gitdown
It’s a good idea to have an application release process that is followed for each new version - there are likely other things that need to be manually reviewed, for example the version number. You could write another script to check for changes in your app, but keep in mind that this also needs to be maintained.