Update README.md to resolve #259
Update README.md to resolve #259

Add usage of `Keen.ready()` wrapper for query and viz examples
ipartola/keen-js,jbpionnier/keen-js,amplii/keen-js,Acidburn0zzz/keen-js,vebinua/keen-js,chrismoulton/keen-js,amplii/keen-js,jbpionnier/keen-js,ruleant/keen-js,lawitschka/keen-js,ruleant/keen-js,ipartola/keen-js,allanbrault/keen-js,vebinua/keen-js,lawitschka/keen-js,Glathrop/keen-js,chrismoulton/keen-js,Glathrop/keen-js,Acidburn0zzz/keen-js,allanbrault/keen-js