[TASK] Migrate Fluid comments from Extbase book (#1963)

Related: TYPO3-Documentation/TYPO3CMS-Book-ExtbaseFluid#536

Documentation/ApiOverview/Fluid/Syntax.rst

@@ -223,3 +223,39 @@ More complex example with chaining:
    {post.date -> f:format.date(format: 'Y-m-d') -> f:format.padding(padLength: 40)}
 
 
+.. _fluid-comments:
+
+Comments
+========
+
+As the Fluid syntax is basically XML, you can use CDATA tags to comment
+out parts of your template:
+
+.. code-block:: html
+   :caption: EXT:my_extension/Resources/Private/Templates/SomeTemplate.html
+
+   <![CDATA[
+   This will be ignored by the Fluid parser
+   ]]>
+
+If you want to hide the contents from the browser, you can additionally
+encapsulate the part in HTML comments:
+
+.. code-block:: html
+   :caption: EXT:my_extension/Resources/Private/Templates/SomeTemplate.html
+
+   <!--<![CDATA[
+   This will be ignored by the Fluid parser and by the browser
+   ]]>-->
+
+Note: This way the content will still be transferred to the browser! If
+you want to completely skip parts of your template, you can make use of
+the **f:comment** view helper. To disable parsing you best combine it
+with CDATA tags:
+
+.. code-block:: html
+   :caption: EXT:my_extension/Resources/Private/Templates/SomeTemplate.html
+
+   <f:comment><![CDATA[
+   This will be ignored by the Fluid parser and won't appear in the source code of the rendered template
+   ]]></f:comment>