changes to section_basics-prerequisites

changed doesn’t to does not
removed attempting and changed to starting
removed each before with and removed ,
added the before ability and changed snap shots to snapshots
added - after roll for roll-back
removed However and changed sentence

Change-Id: Ic011d0b8a35f55f0c3260c13e267ba4d8c6116b9
Merge "changes to section_basics-prerequisites"