inspect: help command

[SUMUKHA-PK]

The help command in the inspect tool must be able to print out all necessary data to guide the user to using the tool well.
Most of this will be sort of documentation of the commands, provided through accessible functions.

Final goal:

> help
<-- print all commands -->
> help commandName
<-- print all details about command -->

All non-supported commands must end gracefully with clear errors (aligning with goals of the inspect tool) and display clear instructions on how to proceed based on what the mistake was.