feature request: final touches for instance switching

[Rexogamer]

What do you want to see?

Following on from #14:

• Automatically reload the app when the user changes the instance URL
• Detect invite links for other known instances - should this also check whether the instance is the current one?
• Potentially make it clearer what instance you're logging into on the log in screen?

[MasicoreLord]

Wouldn't it be better for instances you don't know of a different invite path, to assume it's at appUrl/invite/code?
Obviously the same with bot invite URLs: appUrl/bot/code

[Rexogamer]

It does this already to an extent, but instances may also define their own paths

[MasicoreLord]

True, and wish if possible such paths were configurable in a way that other clients can recognize them, similar to how it could automatically configure stuff like the websocket url.