Improve help text for deprecated 'chia show' commands.

[notpeter]

Purpose:

Improve help text provided by deprecated chia show commands.
Current text suggests running a command which also results in error.
We should suggest a command equivalent to the deprecated command the user ran.

Current Behavior:

$ chia show -c
'chia show -c' has been renamed to 'chia peer -c' 
$ chia peer -c
Usage: chia peer [OPTIONS]
                 {farmer|wallet|full_node|harvester|data_layer|simulator}
Try 'chia peer -h' for help.

Error: Missing argument '{farmer|wallet|full_node|harvester|data_layer|simulator}'. Choose from:
	farmer,
	wallet,
	full_node,
	harvester,
	data_layer,
	simulator

New Behavior:

$ chia show -c
'chia show -c' has been renamed to 'chia peer full_node -c' 
$ chia peer full_node -c
<...snip...command works...>

Testing Notes:

[arvidn]

@notpeter hey, would it be possible for you to sign your commit and force-push it?

[notpeter]

@notpeter hey, would it be possible for you to sign your commit and force-push it?

Done. That check is passing now. I'd suggest y'all update CONTRIBUTING.md to document this policy.