Update the readme with a note on SASS compression.
Update the readme with a note on SASS compression.

flywithmemsl/sinatra-assetpack,jwhitcraft/sinatra-assetpack,rstacruz/sinatra-assetpack,jwhitcraft/sinatra-assetpack,jwhitcraft/sinatra-assetpack,flywithmemsl/sinatra-assetpack,flywithmemsl/sinatra-assetpack,rstacruz/sinatra-assetpack,rstacruz/sinatra-assetpack