message: Remove `auth_code[_pkce]` and `client_creds` modules
diff: //! [spotify-auth-code-pkce]: https://developer.spotify.com/documentation/general/guides/authorization/code-flow
  //! [spotify-implicit-grant]: https://developer.spotify.com/documentation/general/guides/authorization/implicit-grant
  -pub mod auth_code;
  -pub mod auth_code_pkce;
  -pub mod client_creds;
  +mod auth_code;
  +mod auth_code_pkce;
  +mod client_creds;
  pub mod clients;
  // Subcrate re-exports
  