Update Yggdrasil auth configuration docs for authlib-injector path and HTTP settings

[Copilot]

The configuration guide still described the old inline AuthServer shape and did not cover the new authlib-injector options. This updates the docs to match the current Yggdrasil auth configuration written by MCC.

• What changed

  • Replaced the outdated inline-table AuthServer example with the current [Main.General.AuthServer] subsection format
  • Documented the new AuthlibInjectorAPIPath setting for custom authlib-injector prefixes
  • Documented UseHttps for plain-HTTP local or development auth servers
  • Clarified that Host accepts either a hostname or host:port

• Docs updated

  • /docs/guide/configuration.md
  • Expanded the AuthServer entry to describe the full subsection layout, defaults, and practical examples

• Example

  [Main.General.AuthServer]
  Host = "127.0.0.1"
  Port = 25585
  AuthlibInjectorAPIPath = "/authlib-injector"
  UseHttps = false

• Screenshot

  • Updated configuration docs preview: https://github.com/user-attachments/assets/ecba69f6-9924-4fae-8585-d9665016cbe3

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