[ADF-537] Contribution guide start (#2101)
[ADF-537] Contribution guide start (#2101)

* Contribution guide start

* development rebase

* fix link

* fork sync

Alfresco/alfresco-ng2-components,Alfresco/alfresco-ng2-components,Alfresco/alfresco-ng2-components,Alfresco/alfresco-ng2-components