cleaned up training docs module001-ch009-vm-placement

changed the term hostin to host in
changed firstly to first
added "a" between makes and dictionary
changed it's to its
added space to weightsduring
changed some to same

Change-Id: I3402950c5207deb8387e2474c43840f4d93ba6ad
Merge "cleaned up training docs module001-ch009-vm-placement"