Moved board docs to own folder

Tidying up the docs folder.

docs/Boards.md

@@ -30,7 +30,7 @@ These boards are well tested with INAV and are known to be of good quality and r
 It's possible to find more supported and tested boards [here](https://github.com/iNavFlight/inav/wiki/Welcome-to-INAV,-useful-links-and-products)
 ### Boards documentation
 
-See the [docs](https://github.com/iNavFlight/inav/tree/master/docs) folder for additional information regards to many targets in INAV, to example help in finding pinout and features. _Feel free to help improve the docs._
+See the [docs/boards](https://github.com/iNavFlight/inav/tree/master/docs/boards) folder for additional information regards to many targets in INAV, to example help in finding pinout and features. _Feel free to help improve the docs._
 
 ### Boards based on F4/F7 CPUs