Change vuejs to global (#6)

Author: yakimka

README.md

@@ -118,12 +118,14 @@ BetterJsonWidget(
 
 ## Settings
 
-If for some reason you don't want to use bundled Vue.js, you can use `BETTER_JSON_WIDGET_VUE_ESM_URL` settings:
+If for some reason you don't want to use bundled Vue.js, you can change `BETTER_JSON_WIDGET_VUE_URL` settings:
 
 ```python
-BETTER_JSON_WIDGET_VUE_ESM_URL = "https://unpkg.com/vue@3/dist/vue.esm-browser.js"
+BETTER_JSON_WIDGET_VUE_URL = "https://unpkg.com/vue@3"
 ```
 
+If you set this setting to `None`, then bundled Vue.js will not be used.
+
 ## TODO
 
 - Improve JSON Schema support