Remove public access to API routes

[helicalbytes]

On server we can access the api app using its container name as hostname.

The only API endpoint the client website currently uses is the calendar one.

If we create an endpoint in the website which proxies to the API one, then we can remove a need for public API access.

Steps:
(1) Create a proxy endpoint in the website project for the calendar endpoint;
(2) Replace client side calls to use this endpoint;
(3) Don't expose port 3001 in the api container.