updates to docs based on code review and recent changes in update code
updates to docs based on code review and recent changes in update code

anthcp/cdap,caskdata/cdap,hsaputra/cdap,mpouttuclarke/cdap,chtyim/cdap,chtyim/cdap,mpouttuclarke/cdap,hsaputra/cdap,chtyim/cdap,chtyim/cdap,anthcp/cdap,anthcp/cdap,mpouttuclarke/cdap,hsaputra/cdap,hsaputra/cdap,caskdata/cdap,anthcp/cdap,chtyim/cdap,mpouttuclarke/cdap,caskdata/cdap,chtyim/cdap,caskdata/cdap,caskdata/cdap,anthcp/cdap,mpouttuclarke/cdap,caskdata/cdap,hsaputra/cdap