Add parseOptions function

src/endpoints/keywords.ts

@@ -1,5 +1,6 @@
 import { BaseEndpoint } from './base';
 import { BelongingMovies, Keyword, KeywordsOptions } from '../types';
+import { parseOptions } from '../utils';
 
 const BASE_Keyword = '/keyword';
 
@@ -13,9 +14,7 @@ export class KeywordsEndpoint extends BaseEndpoint {
   }
 
   async belongingMovies(keywordId : number, options?: KeywordsOptions): Promise<BelongingMovies> {
-    const params = options
-      ? new URLSearchParams(Object.entries(options)).toString()
-      :  '';
+    const params = parseOptions(options);
     return await this.api.get<BelongingMovies>(`${BASE_Keyword}/${keywordId}/movies?${params}`);
   }
 }