Reorganize site architecture and navigation

[LanesGood]

@d3netxer and @ rory and I met on 12/3/19 to discuss the OSM Stories site, and proposed a new site architecture to emphasize the contributors, and highlight the call for contributions.

Proposed new site architecture + navigation for OSMStories:

• Index/list of stories (with filters)
• Map of stories (with filters)
• Participating organizations
• Submit story button (form page)

[amandasaurus]

🤔 Hi, can you remind me again? Maybe I can't remember your Github username. 12 April 2019 & 3 Dec 2019 I wasn't doing any OSM-y stuff. Did we talk at SotM Heidelberg?

[LanesGood]

@rory Sorry, I tagged the wrong Rory!