Add all pages, make site readable

[FravBox]

Did some more research, figured out most things.

• Added navigation at the top for all pages
• Created all pages and filled all but the PSV one
  • (I think PSV should probably be completely depreciated, but made page anyway just in case)
• Made "Collections" which allow us to display many md files on one page. The collection folders are the ones that start with underscores. You can read more here.
• sort_by in _config.yml for the collections does not work. I do not know why and after a few hours and way too many commits trying to figure it out, I gave up.

You can view current site from my branch here: https://fravbox.github.io/vpr/

All that remains is:

• adding the gifs back to the risk factors
• changing wording in places if you want to
• deciding what to do with the PSV page
• changing style of page, if you want to
• rewriting readme.md for the actual repo
• maybe doing something special to point people to how to contribute easier