Add Google Code-In Participant badge (closes #706)
This commit adds the badge design assets for the Google Code-In badge,
along with a rules file to automate awarding the badge based on
membership of a FAS group. I created the FAS group and made @sumantrom
the owner of it:
https://admin.fedoraproject.org/accounts/group/view/google-codein
This will make it more straightforward to award membership badges,
similar to how we already do it for multiple other groups.
Closes #706.
Signed-off-by: Justin W. Flory <git@jwf.io>