Rewrite readme to suggest using the default server

[tystuyfzand]

The readme still suggests using a private server, which is no longer recommended.

I've added a "Servers" section which isn't part of Installation to make it less involved in the setup process, as well as reworded the "Development" section slightly to make it flow better.

[Genygo]

Hi there!
Could you explain why using private server is not recommended? Do you refer to using an own server or using on public server from an unknown person?

[tystuyfzand]

@Genygo

A lot of the issues lately in Discord are with people using outdated servers, or having issues with servers. It's an outdated section since the official crewlink server is actually stable and online 24/7, while it wasn't before.

You can still use a private server, and some people may prefer it, but for 99.9999% of people to avoid issues (such as being on different servers, outdated servers, etc) it's best to use the official https://crewl.ink server - this is mostly to squash the common misconception that you NEED to run your own server for crewlink to work.

[Genygo]

Thanks for the clarification!