Add API for propagating cursor locations (#61)

frontend/sync-client/src/utils/create-promise.ts

@@ -1,3 +1,7 @@
+/**
+ * A type-safe utility function to create a Promise with resolve and reject functions.
+ * @returns A tuple containing a Promise, a resolve function, and a reject function.
+ */
 export function createPromise<T = void>(): [
 	Promise<T>,
 	(value: T) => void,