docs: @ngx-translate/core v14.x+ support angular 11

Author: damingerdai

README.md

@@ -49,6 +49,7 @@ Choose the version corresponding to your Angular version:
 
  Angular     | @ngx-translate/core | @ngx-translate/http-loader
  ----------- | ------------------- | --------------------------
+ 11          | 14.x+               | 6.x+
  10          | 13.x+               | 6.x+
  9           | 12.x+               | 5.x+
  8           | 12.x+               | 4.x+