CLI: conduit processor-plugins describe PLUGIN

[raulb]

Feature description

This command will describe the processor plugin configuration available.

It does not require having Conduit previously running.

Arguments

Name	Description	Required	Default Value
plugin	processor plugin name	Yes

--help

$ conduit processor-plugins describe PLUGIN

EXAMPLE:

$ conduit processor-plugins describe avro.decode
# auth.basic.password
type: string
description: This option is required if auth.basic.username contains a value. If both auth.basic.username and auth.basic.password are empty basic authentication is disabled.

# auth.basic.username
type: string
...

---

Part of #1911