Added mezzanine-agenda to third party apps list in README.
Added mezzanine-agenda to third party apps list in README.

wbtuomela/mezzanine,Cicero-Zhao/mezzanine,gradel/mezzanine,fusionbox/mezzanine,promil23/mezzanine,theclanks/mezzanine,stephenmcd/mezzanine,douglaskastle/mezzanine,mush42/mezzanine,emile2016/mezzanine,douglaskastle/mezzanine,jjz/mezzanine,eino-makitalo/mezzanine,jerivas/mezzanine,molokov/mezzanine,frankier/mezzanine,dustinrb/mezzanine,agepoly/mezzanine,stephenmcd/mezzanine,webounty/mezzanine,batpad/mezzanine,geodesign/mezzanine,dovydas/mezzanine,wbtuomela/mezzanine,theclanks/mezzanine,ZeroXn/mezzanine,christianwgd/mezzanine,ZeroXn/mezzanine,wyzex/mezzanine,geodesign/mezzanine,jjz/mezzanine,frankier/mezzanine,damnfine/mezzanine,PegasusWang/mezzanine,wyzex/mezzanine,spookylukey/mezzanine,dsanders11/mezzanine,industrydive/mezzanine,frankchin/mezzanine,emile2016/mezzanine,dovydas/mezzanine,viaregio/mezzanine,biomassives/mezzanine,Cajoline/mezzanine,jerivas/mezzanine,dekomote/mezzanine-modeltranslation-backport,jjz/mezzanine,sjuxax/mezzanine,Cajoline/mezzanine,theclanks/mezzanine,molokov/mezzanine,frankchin/mezzanine,emile2016/mezzanine,adrian-the-git/mezzanine,PegasusWang/mezzanine,dekomote/mezzanine-modeltranslation-backport,stephenmcd/mezzanine,SoLoHiC/mezzanine,Skytorn86/mezzanine,Kniyl/mezzanine,dekomote/mezzanine-modeltranslation-backport,spookylukey/mezzanine,eino-makitalo/mezzanine,christianwgd/mezzanine,promil23/mezzanine,adrian-the-git/mezzanine,promil23/mezzanine,saintbird/mezzanine,adrian-the-git/mezzanine,ryneeverett/mezzanine,joshcartme/mezzanine,joshcartme/mezzanine,geodesign/mezzanine,dovydas/mezzanine,mush42/mezzanine,dsanders11/mezzanine,damnfine/mezzanine,readevalprint/mezzanine,sjuxax/mezzanine,ryneeverett/mezzanine,eino-makitalo/mezzanine,Kniyl/mezzanine,vladir/mezzanine,sjuxax/mezzanine,dustinrb/mezzanine,biomassives/mezzanine,PegasusWang/mezzanine,gradel/mezzanine,tuxinhang1989/mezzanine,nikolas/mezzanine,molokov/mezzanine,wyzex/mezzanine,tuxinhang1989/mezzanine,readevalprint/mezzanine,sjdines/mezzanine,viaregio/mezzanine,christianwgd/mezzanine,vladir/mezzanine,vladir/mezzanine,Skytorn86/mezzanine,readevalprint/mezzanine,biomassives/mezzanine,nikolas/mezzanine,Skytorn86/mezzanine,Cajoline/mezzanine,industrydive/mezzanine,ZeroXn/mezzanine,frankchin/mezzanine,SoLoHiC/mezzanine,saintbird/mezzanine,jerivas/mezzanine,sjdines/mezzanine,cccs-web/mezzanine,industrydive/mezzanine,batpad/mezzanine,dsanders11/mezzanine,ryneeverett/mezzanine,AlexHill/mezzanine,spookylukey/mezzanine,mush42/mezzanine,frankier/mezzanine,agepoly/mezzanine,cccs-web/mezzanine,nikolas/mezzanine,webounty/mezzanine,douglaskastle/mezzanine,viaregio/mezzanine,wbtuomela/mezzanine,gradel/mezzanine,damnfine/mezzanine,saintbird/mezzanine,AlexHill/mezzanine,SoLoHiC/mezzanine,Cicero-Zhao/mezzanine,fusionbox/mezzanine,tuxinhang1989/mezzanine,agepoly/mezzanine,dustinrb/mezzanine,Kniyl/mezzanine,webounty/mezzanine,joshcartme/mezzanine,sjdines/mezzanine