integrated keywords endpoint with main TMDB class

src/tmdb.ts

@@ -13,6 +13,7 @@ import {
   ReviewEndpoint,
   TrendingEndpoint,
   FindEndpoint,
+  KeywordsEndpoint,
 } from './endpoints';
 
 export default class TMDB {
@@ -77,4 +78,8 @@ export default class TMDB {
   get find() : FindEndpoint{
     return new FindEndpoint(this.accessToken);
   }
+
+  get keywords() : KeywordsEndpoint{
+    return new KeywordsEndpoint(this.accessToken);
+  }
 }