rewrite installation docs discuss python version discuss all dependencies prefer python 3 in instructions [ci skip]
rewrite installation docs
discuss python version
discuss all dependencies
prefer python 3 in instructions
[ci skip]

drewja/flask,tristanfisher/flask,fkazimierczak/flask,dawran6/flask,dawran6/flask,pallets/flask,fkazimierczak/flask,fkazimierczak/flask,pallets/flask,tristanfisher/flask,mitsuhiko/flask,pallets/flask,mitsuhiko/flask,drewja/flask,drewja/flask