Add Documentation and Help Pages to each Application

Each application will have a documentation and support page.

• Add question mark icon to left of hamburger icon in nshm-apps template.
• Clicking on question mark will render the documentation for the currently active app page
• Content for documentation will be organized by (will accompany) each app
• App documentation will be based on some sort of template that includes generic 'contact us' and other common information; see recent earthquakes webapp