fix(documentation): fix cdn links for bs4 (#6215)

Author: SvetlanaMuravlova

README.md

@@ -111,7 +111,7 @@ You will need to add bootstrap css:
 - `Bootstrap 4`
 ```
 <!--- index.html -->
-<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.3/css/bootstrap.min.css" rel="stylesheet">
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/css/bootstrap.min.css" rel="stylesheet" crossorigin="anonymous" integrity="sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2">
 ```
 
 

libs/common-docs/src/lib/common/documentation/documentation.component.html

@@ -149,9 +149,11 @@ <h4>Manual way</h4>
       <pre class="prettyprint prettyprinted"><span class="com">&lt;!--- index.html --&gt;</span><span
         class="pln"></span>
 <span class="tag">&lt;link</span><span class="pln"> </span><span class="atn">href</span><span class="pun">=</span><span
-          class="atv">"https://maxcdn.bootstrapcdn.com/bootstrap/4.5.3/css/bootstrap.min.css"</span><span
+          class="atv">"https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/css/bootstrap.min.css"</span><span
           class="pln"> </span><span class="atn">rel</span><span class="pun">=</span><span
-          class="atv">"stylesheet"</span><span class="tag">&gt;</span></pre>
+          class="atv">"stylesheet"</span> <span class="atn">crossorigin</span><span class="pun">=</span><span
+          class="atv">"anonymous"</span> <span class="atn">integrity</span><span class="pun">=</span><span
+          class="atv">"sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2"</span><span class="tag">&gt;</span></pre>
 
       <h3>Setting up the bootstrap version manually</h3>
       <p>