Add example integration of data processor for menus to documentation (#79)

Documentation/Index.rst

@@ -18,6 +18,7 @@ Table of Contents
    Features
    Installation
    Configuration
+   Integration
    Changelog
    Maintenance
    Sitemap

Documentation/Integration.rst

@@ -0,0 +1,38 @@
+.. _integration:
+
+===========
+Integration
+===========
+
+Menu with tourist attractions
+=============================
+
+The extension provides a custom page type which references tourist attraction.
+This can be used in conjunction with TYPO3 menus if generated via data processing,
+see 
+
+An concrete example would be to extend the content element ``menu_subpages``:
+
+.. code-block:: typoscript
+
+   tt_content.menu_subpages {
+       dataProcessing {
+           10 {
+               dataProcessing {
+                   20 = WerkraumMedia\ThueCat\Frontend\DataProcessing\ResolveEntities
+                   20 {
+                       as = touristAttraction
+                       if {
+                           isInList.data = field:doktype
+                           value = 950
+                       }
+                       table = tx_thuecat_tourist_attraction
+                       uids.data = flexform:tx_thuecat_flexform:touristAttraction
+                   }
+               }
+           }
+       }
+   }
+
+This will add the additional data processor delivered by the extension.
+It will extend each page of the menu with the model of the referenced tourist attraction.