Moved image feature detection docs into new images section

docs/core_components/images/feature_detection.rst

@@ -1,6 +1,6 @@
-=======================
-Image Feature Detection
-=======================
+=================
+Feature Detection
+=================
 
 Wagtail has the ability to automatically detect faces and features inside your images and automatically crop the images to those features.
 

docs/core_components/images/index.rst

@@ -0,0 +1,8 @@
+Images
+======
+
+.. toctree::
+    :maxdepth: 2
+
+    feature_detection
+

docs/core_components/index.rst

@@ -5,6 +5,7 @@ Core components
     :maxdepth: 2
 
     pages/index
+    images/index
     snippets
     search/index
     form_builder