Add Rector note to deprecations list

Author: dabrt

docs/release_notes/ibexa_dxp_v5.0.md

@@ -353,7 +353,7 @@ Refer to [Ibexa DXP v5.0 renames, deprecations and removals](ibexa_dxp_v5.0_depr
 
 [[% include 'snippets/release_50.md' %]]
 
-To update your application, see the [update instructions](update_from_4.6.md).
+To update your application, see the [update instructions](update_to_5.0.md).
 
 [[= release_note_entry_end() =]]
 

docs/release_notes/ibexa_dxp_v5.0_deprecations.md

@@ -144,6 +144,11 @@ Several field type identifiers have changed.
 
 ## PHP API classes and methods
 
+!!! note "[[= product_name_base =]] Rector"
+
+    [[[= product_name_base =]] Rector package](https://github.com/ibexa/rector) has been introduced that is based on [Rector](https://github.com/rectorphp) and comes with additional rules for working with Ibexa code.
+    You can use it to get rid of PHP code deprecations.
+
 ### `ibexa/admin-ui`
 
 | Old FQN                                              | New FQN / Comment                                                                |