Add a reference about forking in the introduction

Author: openp2pdesign

open.design_definition/open.design.definition.md

@@ -15,7 +15,7 @@ Authorships of this document can be referred to the [Open Design + Hardware (OD+
 This document is the result of the collaborative discussion that has been taking place in the [Open Design + Hardware (OD+H) Working Group](http://design.okfn.org/) of the [Open Knowledge Foundation](http://okfn.org/).
 Please join the conversation about the definition on the [Open Design Definition repository](https://github.com/OpenDesign-WorkingGroup/Open-Design-Definition) and on the [Open Design Working Group mailing list](http://lists.okfn.org/mailman/listinfo/opendesign) (past archives are available [here](http://lists.okfn.org/pipermail/opendesign/)).
 
-This document represents a collaborative experimentation about writing and discussing the definition of Open Design, and should not be understood as a license for Design content. The purpose of this document is to foster discussion, collaboration and community building around the concept and the practice of Open Design. This document clarifies the concepts and applications of Open Design, and while it may make easier the discussion about licenses or other sharing strategies for Design, it is not intended as a license.
+This document represents a collaborative experimentation about writing and discussing the definition of Open Design, and should not be understood as a license for Design content. The purpose of this document is to foster discussion, collaboration and community building around the concept and the practice of Open Design. This document clarifies the concepts and applications of Open Design, and while it may make easier the discussion about licenses or other sharing strategies for Design, it is not intended as a license. Furthermore, the definition can be forked in GitHub for sub-definitions or for alternative development.
 
 
 ### Open Design Statement of Principles