Fix use of response time when sorting

Remove the use of infinity in json

Infinity cannot be represented in json. Using null instead.

Add some explanation about copyable server config

Update servers page style

Using "mustard" for a slightly better look.

Add concurrent server testing plus response time

 - sstester now tests all servers in parallel
 - response time is now measured for each server
 - servers are now sorted by response time
 - hovering over "status dot" in website shows server response time,
   or the error observed for that server.
 - "status dot" size now in em instead of px.

Allow downloading docker-compose file separately

Change connect website header color

Fix API ingress

Add connect website

Fix retry logic in Connect worker