More of a call-to-action voice for forks and pull requests on NCIP

Between

 "We are strongly encouraging forks and pull requests."

and

 "We strongly encourage forks and pull requests."

the former is tentative, the latter a more definitive call to arms.
Merge pull request #226 from randomecho/ncip-encourageable-forks

NCIP post - More of a call-to-action voice for forks and pull requests