Add license and download info to readme.
Add license and download info to readme.

kidaa/flow,kaoree/flow,sdelaysam/flow,lynnmatrix/flow,pyricau/flow,venkatesh3007/flow,leasual/flow,xfumihiro/flow,mlevytskiy/flow,sdelaysam/flow,superboonie/flow,square/flow,Zhuinden/flowless,square/flow