Add image(s) to question/reply

[corywatilo]

As a user, I should be able to add an image to a question/response for clarity.

• Ability to upload image and have it added to the Markdown
• Ability to paste an image from clipboard using Ctrl/Cmd + V
• Clicking an image should expand the image (MVP: open in new window. GA: lightbox?)
• Drag and drop