fix(docs): repoint references to the relocated contributing guide (#107)

fix(docs): repoint references to the relocated contributing guide

The guide moved to .github/CONTRIBUTING.md; these references still
resolved
against the old root location and 404 from where they are written.
Rewritten
using the correct relative depth.

- `QUICKSTART-DEV.adoc`: CONTRIBUTING.md -> .github/CONTRIBUTING.md

Author: hyperpolymath

QUICKSTART-DEV.adoc

@@ -38,4 +38,4 @@ just assail    # run panic-attacker security scan
 
 == Contributing
 
-See link:CONTRIBUTING.md[CONTRIBUTING.md] for guidelines.
+See link:.github/CONTRIBUTING.md[CONTRIBUTING.md] for guidelines.