# Description
This PR adds an indicator when listing subcommands. That indicator tells
whether the command is a plugin, alias, or custom_command.

I changed some of the API to make this work a little easier, namely
`get_signatures()` is now `get_signatures_and_declids()`. It was used in
only one other place (run-external), so I thought it was fine to change
it.
There is a long-standing issue with aliases where they reference the
command name instead of the alias name. This PR doesn't fix that bug.
Example.
```nushell
❯ alias "str fill" = str wrap
```
```nushell
❯ str
... other stuff
Subcommands:
str wrap (alias) - Alias for `str wrap`
str wrap (plugin) - Wrap text passed into pipeline.
```
# User-Facing Changes
Slightly different output of subcommands.