Added defined constants to typedefinition for TypeScript

src/app.d.ts

@@ -4,6 +4,16 @@ import MaintenanceProfile from "$entities/MaintenanceProfile";
 import type TagGroup from "$entities/TagGroup";
 
 declare global {
+  /**
+   * Identifier of the current site this extension is built for.
+   */
+  const __CURRENT_SITE__: string;
+
+  /**
+   * Name of the site.
+   */
+  const __CURRENT_SITE_NAME__: string;
+
   // Helper type to not deal with differences between the setTimeout of @types/node and usual web browser's type.
   type Timeout = ReturnType<typeof setTimeout>;