Add links to the all objects and behaviors pages (#742)

- Don't show in changelog

Author: D8H

docs/gdevelop5/behaviors/index.md

@@ -34,7 +34,7 @@ Here are some commonly used behaviors:
 - [Tween](/gdevelop5/behaviors/tween)
 - [Multiplayer Object](/gdevelop5/all-features/multiplayer)
 
-While these behaviors are often used, the [full list of behaviors available in GDevelop](/gdevelop5/extensions/) keeps growing every day: see the [list of all GDevelop extensions](/gdevelop5/extensions/) to discover them.
+While these behaviors are often used, the [full list of behaviors available in GDevelop](/gdevelop5/behaviors/all-behaviors) keeps growing every day: see the [list of all GDevelop extensions](/gdevelop5/extensions/) to discover them.
 
 Behaviors can be contributed by the community or the GDevelop core development team. You can [create new behaviors](/gdevelop5/behaviors/events-based-behaviors), with or without code, directly inside GDevelop.
 

docs/gdevelop5/objects/index.md

@@ -47,7 +47,7 @@ GDevelop offers a wide variety of objects, each designed for a specific use. Bel
 
 !!! tip
 
-    Many more objects are available through extensions, which you can add from the extension library. Advanced users can also **create their own custom objects**, either to create an entirely new kind of object on the screen or to [assemble multiple objects into one ("prefabs")](/gdevelop5/objects/custom-objects-prefab-template).
+    [Many more objects](/gdevelop5/objects/all-objects) are available through extensions, which you can add from the [extension library](/gdevelop5/extensions). Advanced users can also **create their own custom objects**, either to create an entirely new kind of object on the screen or to [assemble multiple objects into one ("prefabs")](/gdevelop5/objects/custom-objects-prefab-template).
 
 ## Adding an object to your game