Implement oidc client of sorts

internal/conf/conf.go

@@ -60,6 +60,14 @@ type Config struct {
 	NotesDir   string
 	LogAccess  bool
 	Production bool
+	OIDC       struct {
+		ClientID     string `toml:"client_id"`
+		ClientSecret string `toml:"client_secret"`
+		AuthURL      string `toml:"auth_url"`
+		TokenURL     string `toml:"token_url"`
+		RedirectURL  string `toml:"redirect_url"`
+		UserinfoURL  string `toml:"userinfo_url"`
+	}
 }
 
 var (