Added pixel ratio option to the readme documentation.
Added pixel ratio option to the readme documentation.

kidaa/epoch,BoolLi/epoch,fastly/epoch,epochjs/epoch,linearregression/epoch,alol/epoch,fastly/epoch,AssafMentzer/epoch,bontibon/epoch,BoolLi/epoch,kidaa/epoch,linearregression/epoch,alol/epoch,epochjs/epoch,AssafMentzer/epoch,bontibon/epoch