Add trove to command reference

Change-Id: Ie9180ecbf107f82361a7254632869cbba20cf45d
cleaned up module001-ch007-keystone-arch keystone-arch

added space between user and represents
added space between tenant and can

Change-Id: I8fc350d66fed9f0ecdcdf0daa456e1e91396d545
Merge "Add trove to command reference"
Merge "cleaned up module001-ch007-keystone-arch keystone-arch"