doc: fix: docstring: use Promise

frontend/static/js/api/tournament/tournaments.js

@@ -17,7 +17,7 @@ class Tourmanents
 	/**
 	 * 
 	 * @param {Number} id 
-	 * @returns 
+	 * @returns {?Promise<Tournament>}
 	 */
 	async getTournament(id)
 	{
@@ -47,6 +47,7 @@ class Tourmanents
 
 	/**
 	 * @param {String} state must be "finished", or "started", or "waiting". Any other return all elements
+	 * @returns {?Promise<[Tourmanent]>}
 	 */
 	async search(state)
 	{
@@ -76,6 +77,10 @@ class Tourmanents
 		return tournaments;
 	}
 
+	/**
+	 * Get all tournaments
+	 * @returns {?Promise<[Tourmanent]>}
+	 */
 	async all()
 	{
 		return await this.search("");