Ensure "help" is a valid command

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Remove plugins from usage template

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Only show commands in usage if they have a short description

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Align usage command output

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Merge pull request #4 from flynn/usage-updates

Help & usage updates