Collapsible functionality implemented

Client/WebServer/css/docs.css

@@ -324,4 +324,41 @@ a:active.docs-footer-link {
     color: #d9534f;
     background-color: #eee;
     padding: 1 5 1 5;
+  }
+
+  /* Style the button that is used to open and close the docs-collapsible-element content */
+  .docs-collapsible-element {
+    background-color: #fdfdfd;
+    color: #444;
+    cursor: pointer;
+    padding: 18px;
+    width: 100%;
+    border: none;
+    text-align: left;
+    outline: none;
+    font-size: 125%;
+  }
+
+  /* Add a background color to the button if it is clicked on (add the .active class with JS), and when you move the mouse over it (hover) */
+  .active, .docs-collapsible-element:hover {
+    background-color: #eee;
+  }
+
+  /* Style the docs-collapsible-element content. Note: hidden by default */
+  .docs-collapsible-content {
+    padding: 0 18px;
+    display: none;
+    overflow: hidden;
+  }
+
+  .docs-collapsible-element:after {
+    content: '\02795'; /* Unicode character for "plus" sign (+) */
+    font-size: 8px;
+    color: white;
+    float: right;
+    margin-left: 5px;
+  }
+  
+  .docs-collapsible-active:after {
+    content: "\2796"; /* Unicode character for "minus" sign (-) */
   }