[HBASE-24921] Add help output for shell "magic" commands

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: shell
• Assignee: Abhey Rana
• Reporter: Nick Dimiduk
• Created: 20/Aug/20 20:57
• Updated: 04/Sep/20 17:11

Description

The shell has a handful of "magic" commands, things like help and debug, that exist as commands in the shell, but are not implementations of the command class and have no help documentation of their own.

Let's promote them to proper commands, add a new command group, call it "shell command group", for example. This makes them discoverable. Give each of them a help documentation string with examples, as we have for the others, i.e., help 'help'.