Make flag a synonym of flagging
I've reviewed the questions asked in these two tags (including four that used both tags) and see no material difference between them. The end objective is the same: To ask about flags, how to flag, when to flag, how flags work, and why my flag was declined.
I find it interesting these two tags have questions dating back to 2010 and 2011 respectively and to my knowledge this is the first time anyone's noticed the possible tag duplication.
that said, now might be a good time for someone to update the tag wiki.
