Allow Full Markdown Support in Item Descriptions

Allow Full Markdown Support in Item Descriptions

Currently, Item description textarea uses type of WYSIWYG editor where you highlight text and are given the option bold, italicize, etc. It's a bit difficult to use and error prone. Something that would help our team write thorough, clear descriptions is full markdown support in the text area. Not a Hybrid WYSIWYG/Markdown, but just a text area that supports all markdown. Specifically, [Github Flavored Markdown](https://github.github.com/gfm/) would be the most helpful.