Work with markdown files in GTK4

Billy Barrow 424c727cf5 Remove references to CMark namespece on public API %!s(int64=2) %!d(string=hai) anos
src 424c727cf5 Remove references to CMark namespece on public API %!s(int64=2) %!d(string=hai) anos
.gitignore ab05239787 Initial Commit %!s(int64=2) %!d(string=hai) anos
test.md fb772b20a9 Embedded widget improvements %!s(int64=2) %!d(string=hai) anos