Added Plugin Scripts.

After wasting about 2 hours on trying to import the history of these two script files from another repository (and learning stuff about some git commands) I am just adding these files as new.

The output json looks like this: https://github.com/dufferzafar/picard-plugins/blob/master/Plugins.json

To test the scripts, you'll need a folder containing picard plugin files. I have a setup here: https://github.com/dufferzafar/picard-plugins
We can eventually drop the sort_keys and indent args from here, though they're useful during debugging.