Merge pull request #18986 from xcatliu/v4-dev-fix-assets-img-sass

Add prefix to docs/index.html assets/img/sass.png

docs/index.html

@@ -53,17 +53,17 @@ title: Bootstrap · The world's most popular mobile-first and responsive f
 
     <div class="row">
       <div class="col-sm-4 m-b-3">
-        <img src="assets/img/sass.png" alt="Sass support" class="img-fluid">
+        <img src="{{ site.baseurl }}/assets/img/sass.png" alt="Sass support" class="img-fluid">
         <h4>Preprocessor</h4>
         <p>Bootstrap ships with vanilla CSS, but its source code utilizes <a href="http://sass-lang.com/">Sass</a>, a popular CSS preprocessor. Quickly get started with precompiled CSS or build on the source.</p>
       </div>
       <div class="col-sm-4 m-b-3">
-        <img src="assets/img/devices.png" alt="Responsive across devices" class="img-fluid">
+        <img src="{{ site.baseurl }}/assets/img/devices.png" alt="Responsive across devices" class="img-fluid">
         <h4>One framework, every device.</h4>
         <p>Bootstrap easily and efficiently scales your websites and applications with a single code base, from phones to tablets to desktops with CSS media queries.</p>
       </div>
       <div class="col-sm-4 m-b-3">
-        <img src="assets/img/components.png" alt="Components" class="img-fluid">
+        <img src="{{ site.baseurl }}/assets/img/components.png" alt="Components" class="img-fluid">
         <h4>Full of features</h4>
         <p>With Bootstrap, you get extensive and beautiful documentation for common HTML elements, dozens of custom HTML and CSS components, and awesome jQuery plugins.</p>
       </div>