pylint plugin: add overview of plugin documentation
pylint plugin: add overview of plugin documentation

Plexxi/st2,nzlosh/st2,StackStorm/st2,nzlosh/st2,StackStorm/st2,Plexxi/st2,StackStorm/st2,Plexxi/st2,StackStorm/st2,Plexxi/st2,nzlosh/st2,nzlosh/st2