Replace codesandbox links with an embed

docs/get-started-angular.md

@@ -15,11 +15,8 @@ This step-by-step tutorial will help you get started with SurveyJS Dashboard in
 
 As a result, you will create the following dashboard:
 
-<iframe src="https://codesandbox.io/p/sandbox/add-surveyjs-analytics-to-an-angular-application-forked-n2yt2m"
-  style="width:100%; height:500px; border:0; border-radius: 4px; overflow:hidden;"
-  title="Add SurveyJS Dashboard to an Angular Application"
-  allow="accelerometer; ambient-light-sensor; camera; encrypted-media; geolocation; gyroscope; hid; microphone; midi; payment; usb; vr; xr-spatial-tracking"
-  sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
+<iframe src="/proxy/github/code-examples/get-started-analytics/knockout/index.html"
+    style="width:100%; border:0; border-radius: 4px; overflow:hidden;"
 ></iframe>
 
 [View Full Code on GitHub](https://github.com/surveyjs/code-examples/tree/main/get-started-analytics/angular (linkStyle))

docs/get-started-knockout-jquery.md

@@ -14,12 +14,9 @@ This step-by-step tutorial will help you get started with SurveyJS Dashboard in
 
 As a result, you will create the following dashboard:
 
-<p class="codepen" data-height="532.7999572753906" data-default-tab="js,result" data-slug-hash="vYdmvgz" data-user="romantsukanov" style="height: 532.7999572753906px; box-sizing: border-box; display: flex; align-items: center; justify-content: center; border: 2px solid; margin: 1em 0; padding: 1em;">
-  <span>See the Pen <a href="https://codepen.io/romantsukanov/pen/vYdmvgz">
-  SurveyJS - Add SurveyJS Dashboard to a Knockout or jQuery Application</a> by RomanTsukanov (<a href="https://codepen.io/romantsukanov">@romantsukanov</a>)
-  on <a href="https://codepen.io">CodePen</a>.</span>
-</p>
-<script async src="https://cpwebassets.codepen.io/assets/embed/ei.js"></script>
+<iframe src="/proxy/github/code-examples/get-started-analytics/knockout/index.html"
+    style="width:100%; border:0; border-radius: 4px; overflow:hidden;"
+></iframe>
 
 SurveyJS Dashboard is powered by Knockout and does not have an individual implementation for jQuery. However, you can integrate the version for Knockout into your jQuery application by following the same instructions.
 

docs/get-started-react.md

@@ -15,11 +15,8 @@ This step-by-step tutorial will help you get started with SurveyJS Dashboard in
 
 As a result, you will create the following dashboard:
 
-<iframe src="https://codesandbox.io/p/sandbox/add-surveyjs-analytics-to-a-react-application-forked-kj95pt"
-    style="width:100%; height:500px; border:0; border-radius: 4px; overflow:hidden;"
-    title="Add SurveyJS Dashboard to a React Application"
-    allow="accelerometer; ambient-light-sensor; camera; encrypted-media; geolocation; gyroscope; hid; microphone; midi; payment; usb; vr; xr-spatial-tracking"
-    sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
+<iframe src="/proxy/github/code-examples/get-started-analytics/knockout/index.html"
+    style="width:100%; border:0; border-radius: 4px; overflow:hidden;"
 ></iframe>
 
 [View Full Code on GitHub](https://github.com/surveyjs/code-examples/tree/main/get-started-analytics/react (linkStyle))

docs/get-started-vue.md

@@ -15,11 +15,8 @@ This step-by-step tutorial will help you get started with SurveyJS Dashboard in
 
 As a result, you will create the following dashboard:
 
-<iframe src="https://codesandbox.io/p/sandbox/add-surveyjs-analytics-to-a-vue-application-forked-jj6hgn"
-    style="width:100%; height:500px; border:0; border-radius: 4px; overflow:hidden;"
-    title="trusting-varahamihira-rx7o0k"
-    allow="accelerometer; ambient-light-sensor; camera; encrypted-media; geolocation; gyroscope; hid; microphone; midi; payment; usb; vr; xr-spatial-tracking"
-    sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
+<iframe src="/proxy/github/code-examples/get-started-analytics/knockout/index.html"
+    style="width:100%; border:0; border-radius: 4px; overflow:hidden;"
 ></iframe>
 
 [View Full Code on GitHub](https://github.com/surveyjs/code-examples/tree/main/get-started-analytics/vue (linkStyle))