[FEATURE] how time support command arg `--add-plugin`

[8MiYile]

--add-extra-plugin-jar, --add-plugin    Specify paths to extra plugin jars to 
  <File: Jar file>                        be loaded in addition to those in   
                                          the plugins folder. This argument   
                                          can be specified multiple times,    
                                          once for each extra plugin jar path.

how to support this
this from paper

[juanmuscaria]

Currently, command parsing is a brittle mess. We should make a pass through it first before adding crucible specific arguments.