Swap out YAML and other config loaders with Lua 5.4 compatible ones

[alerque]

Currently there are some optional dependencies including on yaml that are not Lua 5.4 compatible. These should be made easier to swap out for a loader of choice including a YAML reader that works in Lua 5.4, or works with pure Lua, or whatever.

[Tieske]

That module has gone unmaintained, the more common one is https://github.com/gvvaughan/lyaml I think. Not sure it supports Windows though.