provide a .md template alongside the .rst one

[nanuxbe]

As suggested in this forum thread and this mastodon thread and probably many other places (I know the topic has been brought up several times on the forum, only have this one link).

The .md file was mostly generated using pandoc (only alterating the head of the file). Changes have also been made to the .rst template as well as DEP-1 in order to point to the markdown template, while the markdown template also points to the restructured text one