Atsuko's grin

BUR #39234 is pending approval.

rename atsuko's_grin_(meme) -> atsuko's_grin
mass update atsuko's_grin -> -meme

Essex face is not a meme, neither are both Mutsuki faces, yaranaika etc. So why this one should be?

I still don't know what are the criteria between an inside fandom jokes or an actual memes. I've proposed long ago to turn Yaranaika into proper meme tag since it has significant notoriety but it got rejected.

If we were to exclude in-jokes, then I guess Poison Yuuka and Big eared Miyabi should also be excluded as well.