message: change azure cdn to unpkg
diff: @@ -145,13 +145,13 @@ Vue version:
  npm install survey-vue
  ```
  -Or use Azure CDN:
  +Or use unpkg CDN:
  -* https://surveyjs.azureedge.net/{version-number}/survey.angular.min.js
  -* https://surveyjs.azureedge.net/{version-number}/survey.ko.min.js
  -* https://surveyjs.azureedge.net/{version-number}/survey.react.min.js
  -* https://surveyjs.azureedge.net/{version-number}/survey.jquery.min.js
  -* https://surveyjs.azureedge.net/{version-number}/survey.vue.min.js
  +* https://unpkg.com/survey-angular@{version-number}/survey.angular.min.js
  +* https://unpkg.com/survey-knockout@{version-number}/survey.ko.min.js
  +* https://unpkg.com/survey-react@{version-number}/survey.react.min.js
  +* https://unpkg.com/survey-jquery@{version-number}/survey.jquery.min.js
  +* https://unpkg.com/survey-vue@{version-number}/survey.vue.min.js
  You find all versions/builds in the [surveyjs/build repo](https://github.com/surveyjs/builds).
  