docs(contributing): add selenium install guide [skip npm]
docs(contributing): add selenium install guide [skip npm]

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