Clarify the python versions that flask supports
Clarify the python versions that flask supports

karlw00t/flask,hyunchel/flask,tristanfisher/flask,wldtyp/flask,karlw00t/flask,tristanfisher/flask,mitsuhiko/flask,antsar/flask,AvivC/flask,nZac/flask,lord63-forks/flask,lord63-forks/flask,pallets/flask,adrianmoisey/cptdevops,adrianmoisey/cptdevops,drewja/flask,drewja/flask,iamantee/flask,auready/flask,AvivC/flask,Parkayun/flask,fkazimierczak/flask,fkazimierczak/flask,pallets/flask,dawran6/flask,drewja/flask,fengsp/flask,hyunchel/flask,gaomingnudt/gm-flask2.0,iamantee/flask,dawran6/flask,Parkayun/flask,auready/flask,nZac/flask,mitsuhiko/flask,antsar/flask,fkazimierczak/flask,gaomingnudt/gm-flask2.0,Endika/flask,wldtyp/flask,garaden/flask,fengsp/flask,Endika/flask,garaden/flask,pallets/flask