Document that we now support GitHub. Also, change .md files
to use ~~~~ instead of `...` because that's friendlier to
people who want to cut-and-paste commands.
Signed-off-by: David A. Wheeler <dwheeler@dwheeler.com>
Merge in a nice long set of improvements from:
https://github.com/nickthetait/flawfinder/
A BIG thanks goes to Nicholas Tait (nickthetait).
Signed-off-by: David A. Wheeler <dwheeler@dwheeler.com>