Added in ability to customise server list

[thomaspreece]

Quick Pull Request to allow you to provide custom server list via env.yaml file if user needs to (this is useful for when you want to be able to quickly load presets for private servers).

Also made some minor UI changes:

• Any value that is missing when selecting from the server list will no longer result in bubbles that show no value i.e. "Location: "
• The header is no longer sticky. On mobile devices/small screens having a sticky header take up too much of the screen.