chore(theme): remove default light theme

The app doesn't support the built-in white theme provided by Element. In future, a custom elecord white theme would need to be developed.

Author: hazzuk

src/theme.ts

@@ -87,7 +87,7 @@ export function isHighContrastTheme(theme: string): boolean {
 
 export function enumerateThemes(): { [key: string]: string } {
     const BUILTIN_THEMES = {
-        "light": _t("common|light"),
+        // "light": _t("common|light"), /* elecord, remove default light theme */
         "light-high-contrast": _t("theme|light_high_contrast"),
         "dark": _t("common|dark"),
     };