fix(guide): simplify directory structure

guide/english/certifications/front-end-libraries/bootstrap/apply-the-default-bootstrap-button-style/index.md

@@ -0,0 +1,40 @@
+---
+title: Apply the Default Bootstrap Button Style
+---
+## Apply the Default Bootstrap Button Style
+
+The last challenge had you creating 6 buttons, 3 in each well element, this time you are required to add classes to those buttons.
+
+### Hint
+
+A class is declared using the following syntax:
+
+```html
+<button class="class(es)Name"></button>
+```
+
+### Solution
+
+Since you have to add the ``` btn ``` and ``` btn-default ``` classes, the following is the solution:
+
+```html
+<div class="container-fluid">
+  <h3 class="text-primary text-center">jQuery Playground</h3>
+  <div class="row">
+    <div class="col-xs-6">
+      <div class="well">
+        <button class="btn btn-default"></button>
+        <button class="btn btn-default"></button>
+        <button class="btn btn-default"></button>
+      </div>
+    </div>
+    <div class="col-xs-6">
+      <div class="well">
+        <button class="btn btn-default"></button>
+        <button class="btn btn-default"></button>
+        <button class="btn btn-default"></button>
+      </div>
+    </div>
+  </div>
+</div>
+```