Spelling mistake (#186)

Correct spelling mistake in edgeconnector.md

Author: ngammarano

hardware/edgeconnector.md

@@ -258,7 +258,7 @@ There are also some nice ideas that have surfaced in the community such as using
 
 Can you help to find or design a better connection solution to the micro:bit edge connector? Share your designs and discoveries with us!
 
-## Edge Connnectors for the BBC micro:bit
+## Edge Connectors for the BBC micro:bit
 
 [Add your connector to our list](http://github.com/microbit-foundation/dev-docs/edit/master/hardware/edgeconnector.md){: .btn.sm-btn}