Arduino for STM32

Thanks a lot for the pointers!

I've made a "vendor" that references the STMicrosystems core and added one board for now, and that's working well for me. I will try how this works with other users, but it feels like the right way to go.

So I've created a board variant, and it's working for me locally. :)

I'm wondering what the best way is to distribute it to other people?

Of course I could send a pull-request to the official STM32 core repository, wait for it to be approved and merged, wait for the next release, and then people ...