Convert reStructuredText to Markdown

[GeckoEidechse]

Initial version by @Caznix, fixups by @GeckoEidechse

Converts the reStructuredText syntax to Markdown with an effort to keep the diff as minimal as possible in the process as long as mkdocs still renders it correctly.
This means that for example inline code segments that use double backticks were kept as is for now

``inline code``

instead of changing to single backticks which is more common in markdown

`inline code`

Co-authored-by: Cazdotsys [email protected]

[GeckoEidechse]

Went through all files again and made sure to reduce the diff as much as possible while also ensuring that everything still renders correctly with mkdocs.

[GeckoEidechse]

Merging based on the fact that after prompting the involved people with enough time to respond there were no requests for changes ^^