optimize introduction plugin , change to use annotations to get plugin description.

[Sivyer]

Feature Request

optimize introduction plugin , change to use annotations to get plugin description.

Motivation

To make introduction plugin more flexible by use annotation to collection plugin description.

Implementation

Add a annotation that use in plugins.
Define a bean processor to collection annotation field then fill them into collections.
Rewrite getting plugin description logic in introduction plugin.

Assignment

i'll make this myself.