Hi Wim,
Yes I confirm.
For the moment I implemented following possibilities:
The web-server which hosts the website contains the static web pages as wells as the corresponding md.files which are either located in git/github or in a distinct directory on the website. Clicking on the “Edit this page” link on a web page calls a md editor. If php is activate on the website you can edit the md.file and submit it either to git/gihub or back to is directory from where it was loaded. If there is no php available the md.file can be locally downloaded, edited and from there pushed to git/github again. Github has two roles it’s a repo and a webserver.
That’s what I tried to show in the graphic below:

In short: local development with git. If there are more than one person working on the website the md-files are to be merged and versioned with github. The deployment and life-test is don on a staged website. If everything is ok the result is deployed to the life website.
I hope that my explanation was understandable. Don’t hesitate to ask any question.
Best
Christophe