The original header was exactly 80-columns which made every file format
with a line-start comment syntax reflow the text. Instead, pick
a canonical re-flowing that keeps it to just three lines. This also lets
the text refer to the project which seems more clear.
No practical or semantic change here, just getting consistent wording
and line breaks for regularity.
CONTRIBUTING.md replaces the mention of Google style guide (which isn't automated) with Prettier (which should do most of the hauling). The rest is the formatter.
Jon Meow
Chandler Carruth