Typo fix in web-ui-rest-api.md

Author: David Dumenil <david.dumenil@moneysupermarket.com>

Reviewers: Xinyu <xinyu@apache.org>

Closes #10 from daviddumenil-msm/patch-1
diff --git a/docs/learn/documentation/versioned/jobs/web-ui-rest-api.md b/docs/learn/documentation/versioned/jobs/web-ui-rest-api.md
index 8449403..131b08a 100644
--- a/docs/learn/documentation/versioned/jobs/web-ui-rest-api.md
+++ b/docs/learn/documentation/versioned/jobs/web-ui-rest-api.md
@@ -45,7 +45,7 @@
   </thead>
   <tbody>
     <tr>
-      <td>/metrics</td><td>HahsMap that represents metrics for every 60 seconds.</td>
+      <td>/metrics</td><td>HashMap that represents metrics for every 60 seconds.</td>
     </tr>
     <tr>
       <td>/task-context</td><td>HashMap that provides information about task context including task name and task ID.</td>