Added docs in js files and fixed some minor visual bugs (#118)

Co-authored-by: Adam Bem <adam.bem@zoho.eu>
Reviewed-on: R11/release11-tools-web#118

Frontend/tools/xpath.html

@@ -21,7 +21,7 @@
                 </div>
 
                 <div class="display-space-between">
-                    <div style="text-align: center;">
+                    <div>
                         <label for="processors">Select XPath processor:</label>
                         <select name="processors" id="processors">
                             <option value="saxon">Saxon</option>
@@ -45,7 +45,7 @@
                             onclick="fillDefaultXML(this)">Insert default XML</button>
                     </div>
                 </div>
-                <!-- <br><br> -->
+                <br>
                 <label for="xmlArea"><b>Insert your XML:</b></label>
                 <textarea id="xmlArea" name="xmlArea" rows="15"
                     class="textarea-300 bordered-field vertically-resizeable max-width"