UPDATE: Adds web app (#79)

Things missing:

* Browse mode
* Front end tests
* Storybook

base/src/lib.rs

@@ -57,4 +57,5 @@ pub mod mock_time;
 
 pub use model::get_milliseconds_since_epoch;
 pub use model::Model;
+pub use user_model::BorderArea;
 pub use user_model::UserModel;