fixed bugs in form button sizes

when I saw your webpage I found bugs in button size where the medium-size button is smaller than the small-size button. So I fixed that bug

production/form_buttons.html

@@ -594,18 +594,18 @@
                   <div class="buttons">
                     <!-- Standard button -->
                     <button type="button" class="btn btn-secondary btn-lg">Large Button</button>
-                    <button type="button" class="btn btn-secondary btn-sm">Medium Button</button>
+                    <button type="button" class="btn btn-secondary btn-xs">Medium Button</button>
-                    <button type="button" class="btn btn-secondary btn-xs">Small Button</button>
+                    <button type="button" class="btn btn-secondary btn-sm">Small Button</button>
                     <br>
 
                     <button type="button" class="btn btn-success btn-lg">Large Button</button>
-                    <button type="button" class="btn btn-success btn-sm">Medium Button</button>
+                    <button type="button" class="btn btn-success btn-xs">Medium Button</button>
-                    <button type="button" class="btn btn-success btn-xs">Small Button</button>
+                    <button type="button" class="btn btn-success btn-sm">Small Button</button>
                     <br>
 
                     <button type="button" class="btn btn-info btn-lg">Large Button</button>
-                    <button type="button" class="btn btn-info btn-sm">Medium Button</button>
+                    <button type="button" class="btn btn-info btn-xs">Medium Button</button>
-                    <button type="button" class="btn btn-info btn-xs">Small Button</button>
+                    <button type="button" class="btn btn-info btn-sm">Small Button</button>
                     <br>
                   </div>
                 </div>