Flags: help

[steveklabnik]

This issue is part of #125

-h/--help: help

Using this flag looks like this:

$ rustdoc -h
$ rustdoc --help

This will show rustdoc's built-in help, which largely consists of
a list of possible command-line flags.

Some of rustdoc's flags are unstable; this page only shows stable
options, --help will show them all.

---

Should we keep this flag or not?

[steveklabnik]

I can't imagine we don't keep this.

Maybe we want a subcommand now though?

[euclio]

Clap automatically provides both.

[mgattozzi]

Yeah we can pretty much close this one and #127 because of clap.

[steveklabnik]

Nice!