stlink: added 1.0.0 release

This is to add a new formula `stlink`, previously attempted at #14175 by @henryeherman two years back. Build system has then changed to autoconf/automake, and now it comes with a (relatively) stable tag back in February.

First attempt in making a brew - please advise if anything's wrong here. Thanks.
Thanks! Frankly I am not very sure what would be a better test though. `stlink` is in fact a hardware programmer. In earlier versions I have tried to use `st-info`, which in fact prints hardware info, however it won't quite work if there are no hardware plugged into the machine...

Any ideas?