Updates README with current trove help output

Reasons:
- trove help section in README shows old options, trove help message
  has changed now, and the section needs the update.

Changes:
- Updates the trove help section in README.
- The updates have been picked up from latest trove help output.

Change-Id: I37b6f3ad5d3ac0497eec179a4de447e5b39fb215
Closes-Bug: #1322819
Merge "Updates README with current trove help output"