[DOCS] Add guide for New Content Element Wizard customization

Documentation/Guides/Index.rst

@@ -19,4 +19,4 @@ functionality.
    CropVariants
    RTEConfig
    UseExistingTCAFields
-   Labels
+   NewContentElementWizard

Documentation/Guides/NewContentElementWizard.rst

@@ -0,0 +1,45 @@
+.. include:: ../Includes.txt
+
+.. _labels-guide:
+.. _new-content-element-wizard-guide:
+
+========================================
+New Content Element Wizard customization
+========================================
+
+Per default, all Mask Content Elements are grouped in "Mask Elements". If you
+want to group your elements in different tabs, you can do this by overriding
+page TsConfig. Unfortunately, Mask doesn't provide a proper API for this, so
+it looks a little tricky to do. You can also use this example to simply change
+the label of the Mask group. See the comments in the code.
+
+.. code-block:: typoscript
+
+   mod.wizards.newContentElement.wizardItems {
+       # Create new custom group
+       myOtherGroup {
+           header = My other Group
+           after = mask
+           # Copy config of Mask elements
+           elements.mask_element_1 < mod.wizards.newContentElement.wizardItems.mask.elements.mask_element_1
+           elements.mask_element_2 < mod.wizards.newContentElement.wizardItems.mask.elements.mask_element_2
+           elements.mask_element_3 < mod.wizards.newContentElement.wizardItems.mask.elements.mask_element_3
+           # Add to show list
+           show = mask_element_1,mask_element_2,mask_element_3
+       }
+
+       mask {
+           # Override title of the Mask group
+           header = My Elements
+           before = common
+           # Remove all elements, which shouldn't be here.
+           elements.mask_element_1 >
+           elements.mask_element_2 >
+           elements.mask_element_3 >
+       }
+   }
+
+.. note::
+
+   This does not work inside the newly introduced :file:`page.tsconfig` file in
+   TYPO3 v12.