Migration to GitHub Discussions

[jimmo]

First time users of Micropython Github will probably be unsure how to or where to ask, and how to appropriately format py code... And having first time users having to go off tangent and do research on using Github Discussions might in some instances be off putting to some and choose not engage...? Just a thought...

I have tried to address some of this in the "Welcome" post -- the link to this is one of the most prominient things on the overview page at https://github.com/micropython/micropython/discussions

Certainly the python formatting and the purpose of the various categories. If there are more things you think I should add here, can definitely do so!