[ZEPPELIN-2949] Updated documentation

docs/interpreter/spark.md

@@ -145,6 +145,11 @@ You can also set other Spark properties which are not listed in the table. For a
     <td>true</td>
     <td>Do not change - developer only setting, not for production use</td>
   </tr>
+  <tr>
+  <td>zeppelin.spark.uiWebUrl</td>
+    <td></td>
+    <td>Override Spark UI default URL</td>
+  </tr>
 </table>
 
 Without any configuration, Spark interpreter works out of box in local mode. But if you want to connect to your Spark cluster, you'll need to follow below two simple steps.

spark/src/main/resources/interpreter-setting.json

@@ -67,6 +67,13 @@
         "defaultValue": true,
         "description": "Do not change - developer only setting, not for production use",
         "type": "checkbox"
+      },
+      "zeppelin.spark.uiWebUrl": {
+        "envName": null,
+        "propertyName": "zeppelin.spark.uiWebUrl",
+        "defaultValue": "",
+        "description": "Override Spark UI default URL",
+        "type": "string"
       }
     },
     "editor": {