cli: (sub)command aliases

[dgw]

Requested Feature

Sometimes I find myself wishing that there was a more concise way to express Sopel CLI actions, e.g. sopel-plugins e pluginname.

Problems Solved

It just saves typing. I thought of this idea (again) while messing with my bot over ssh from a smartphone.

Alternatives

I thought of having subcommands support stemming—any unambiguous sequence that doesn't overlap with another subcommand—but as far as I can tell argparse doesn't support it. (There is allow_abbrev for long option names, but it doesn't apply to subparsers/subcommands.)

Notes

There is an aliases kwarg to add_parser() in argparse, which would let us define shorter aliases for subcommands.

I haven't looked at top-level command aliases yet, but maybe those would be better left to users' shell config (we could provide a sample bashrc etc. snippet).