docs(reamde): add license into readme

Raiper34 · Raiper34 · commit ffaaec36c3eb · 2022-09-11T16:55:11.000+02:00
diff --git a/README.md b/README.md
@@ -110,3 +110,6 @@ import {FocusHistoryService} from 'ngx-focus-control';
 ...
 constructor(public readonly focusHistoryService: FocusHistoryService) { }
 ```
+
+# License
+MIT
