> There are definitely wikis which use fairly simple markup > (e.g. markdown) and can usefully be read and updated online via a web > interface and git offline or online. The one I'm most familiar with is > ikiwiki (available in guix), though don't have a lot of experience > updating it via the web interface.
It looks like the web interface is simple yet sufficient, basically a text box and then the buttons you'd expect: submit, preview, add/remove attachment. It uses the usual markdown syntax and can support others using plugins. https://ikiwiki.info/ikiwiki/formatting/ The default style is pretty bare bones, but I imagine it could be made to match the Guix theme. Great suggestion!