docs(readme): simplify samples links
docs(readme): simplify samples links

bbender/spark-js-sdk,aimeex3/spark-js-sdk,adamweeks/spark-js-sdk,adamweeks/spark-js-sdk,mwegman/spark-js-sdk,mwegman/spark-js-sdk,adamweeks/spark-js-sdk,bbender/spark-js-sdk,aimeex3/spark-js-sdk,mwegman/spark-js-sdk,aimeex3/spark-js-sdk,bbender/spark-js-sdk