Minor cleanup

docs/hooks/hook_civicrm_alterMailContent.md

@@ -19,15 +19,17 @@ tokenizing it.
 
 ## Example
 
-    /**
-     * Implement hook_civicrm_alterMailContent
-     *
-     * Replace invoice template with custom content from file
+```php
+   /**
+    * Implement hook_civicrm_alterMailContent
+    *
+    * Replace invoice template with custom content from file
     */
-    function mail_civicrm_alterMailContent(&$content) {
-      if (CRM_Utils_Array::value('valueName', $content) == 'contribution_invoice_receipt') {
-        $path = CRM_Core_Resources::singleton()->getPath('org.myorg.invoice');
-        $html = file_get_contents($path.'/msg/contribution_invoice_receipt.html.tpl');
-        $content['html'] = $html;
-      }
+  function mail_civicrm_alterMailContent(&$content) {
+    if (CRM_Utils_Array::value('valueName', $content) == 'contribution_invoice_receipt') {
+      $path = CRM_Core_Resources::singleton()->getPath('org.myorg.invoice');
+      $html = file_get_contents($path.'/msg/contribution_invoice_receipt.html.tpl');
+      $content['html'] = $html;
     }
+  }
+```