Revert removal of "new" usage recommendations in HACKING.
Revert removal of "new" usage recommendations in HACKING.

The entire code base follows this recommendation and removing it implicitly
contradicts the primary rule of matching the existing style.

nathyong/dactyl,madand/pentadactyl-pm,Evidlo/vimperator-labs,airodactyl/dactyl,5digits/dactyl,Kjwon15/dactyl,mcarton/vimperator-labs,airodactyl/dactyl,derenio/vimperator-labs,Kjwon15/dactyl,nathyong/dactyl,Quicksaver/vimperator-labs,moonshadow/dactyl,invl/dactyl,airodactyl/dactyl,Kjwon15/dactyl,madand/pentadactyl-pm,nullren/vimperator-labs,invl/dactyl,invl/dactyl,moonshadow/dactyl,Sheile/vimperator-labs,paretje/vimperator-labs,airodactyl/airodactyl,derenio/vimperator-labs,madand/pentadactyl-pm,nathyong/dactyl,seanmorton/vimperator-labs,nullren/vimperator-labs,invl/dactyl,airodactyl/dactyl,madand/pentadactyl-pm,airodactyl/dactyl,invl/dactyl,moonshadow/dactyl,madand/pentadactyl-pm,nathyong/dactyl,moonshadow/dactyl,zklinger/vimperator-labs,seanmorton/vimperator-labs,nathyong/dactyl,mcarton/vimperator-labs,stemar94/vimperator-labs,invl/dactyl,Kjwon15/dactyl,5digits/dactyl,stemar94/vimperator-labs,paretje/vimperator-labs,Kjwon15/dactyl,airodactyl/dactyl,Kjwon15/dactyl,madand/pentadactyl-pm,zklinger/vimperator-labs,Evidlo/vimperator-labs,moonshadow/dactyl,nathyong/dactyl,5digits/dactyl,airodactyl/airodactyl,moonshadow/dactyl,5digits/dactyl,5digits/dactyl,Quicksaver/vimperator-labs,Sheile/vimperator-labs,5digits/dactyl