Fix code block formatting (SharePoint#2266)

Author: junian

docs/sp-add-ins/update-add-in-web-components-in-sharepoint.md

@@ -192,7 +192,7 @@ Because there is already such an element in the **ElementManifests** section, si
 
    3. Add the following markup to the **asp:Content** element, and then replace _{RelativePathToNewPageFile}_ with the new path and file name. This script redirects the browser to the new page and includes the query parameters. It also keeps the old page out of the browser history.
 
-       ```
+       ```html
         <script type="text/javascript">
               var queryString = window.___location.search.substring(1);
               window.___location.replace("{RelativePathToNewPageFile}" + "?" + queryString);
@@ -274,25 +274,24 @@ For the most part, this is exactly what should occur: you want every earlier ver
 
    Each time that you upgrade the Feature, follow the same pattern. Add a new **VersionRange** for the latest update actions. Add an **EndVersion** element to the _previous_ **VersionRange** element and set it to the previous version number. In the continuing example, the file would resemble the following for the update from 3.0.0.0 to 4.0.0.0.
 
-     
     ```XML
-        <Feature <!-- Some attributes omitted --> 
-                       Version="4.0.0.0">
-          <ElementManifests>
-            <!-- Child elements omitted -->
-          </ElementManifests>
-          <UpgradeActions>
-            <VersionRange EndVersion="2.0.0.0">
-               <!-- Child elements for upgrade from 1.0.0.0 to 2.0.0.0 go here. -->
-            </VersionRange>
-            <VersionRange EndVersion="3.0.0.0">
-               <!-- Child elements for upgrade from 2.0.0.0 to 3.0.0.0 go here. -->
-            </VersionRange>
-            <VersionRange>
-               <!-- Child elements for upgrade from 3.0.0.0 to 4.0.0.0 go here. -->
-            </VersionRange>
-          </UpgradeActions>
-        </Feature>
+    <Feature <!-- Some attributes omitted --> 
+                    Version="4.0.0.0">
+      <ElementManifests>
+        <!-- Child elements omitted -->
+      </ElementManifests>
+      <UpgradeActions>
+        <VersionRange EndVersion="2.0.0.0">
+            <!-- Child elements for upgrade from 1.0.0.0 to 2.0.0.0 go here. -->
+        </VersionRange>
+        <VersionRange EndVersion="3.0.0.0">
+            <!-- Child elements for upgrade from 2.0.0.0 to 3.0.0.0 go here. -->
+        </VersionRange>
+        <VersionRange>
+            <!-- Child elements for upgrade from 3.0.0.0 to 4.0.0.0 go here. -->
+        </VersionRange>
+      </UpgradeActions>
+    </Feature>
     ```
 
    Notice that the most recent **VersionRange** element has no **BeginVersion** or **EndVersion** attributes. This ensures that the upgrade actions that go into this **VersionRange** element are applied to all previous versions of the Feature, which is what you want because all the latest changes are referenced in this **VersionRange**, and none of them have already occurred for any instance of the Feature.