Change git commit message explanation link
Change git commit message explanation link

I think the new link explains why a good git commit message is important
pretty well. It links to the old link, so there's no loss of information
in changing the one we link to in our docs.

mozilla/fjord,Ritsyy/fjord,hoosteeno/fjord,mozilla/fjord,hoosteeno/fjord,hoosteeno/fjord,lgp171188/fjord,mozilla/fjord,Ritsyy/fjord,mozilla/fjord,Ritsyy/fjord,hoosteeno/fjord,Ritsyy/fjord,lgp171188/fjord,lgp171188/fjord,lgp171188/fjord