Added docs to popup list and popup id counter.

packages/frontend/src/os.ts

@@ -136,7 +136,16 @@ export function promiseDialog<T extends Promise<any>>(
 	return promise;
 }
 
+/**
+ * Counter for generating unique popup IDs.
+ * @type {number}
+ */
 let popupIdCount = 0;
+
+/**
+ * A reactive list of the currently opened popups. This is used in a Vue component
+ * in a v-for loop to render the popups.
+ */
 export const popups = ref<{
 	id: number;
 	component: Component;