Add back documentation link mapping for the join_shapes operator

modules/rna_manual_reference.py

@@ -430,7 +430,8 @@ url_manual_mapping = (
 	("bpy.ops.mesh.loopcut_slide*", "modeling/meshes/editing/subdividing/loop.html#bpy-ops-mesh-loopcut-slide"),
 	("bpy.ops.mesh.primitive*add*", "modeling/meshes/primitives.html#bpy-ops-mesh-primitive-add"),
 	("bpy.ops.object.gpencil_add*", "grease_pencil/primitives.html#bpy-ops-object-gpencil-add"),
-	("bpy.ops.object.*shape_key_*",  "animation/shape_keys/shape_keys_panel.html"),
+	("bpy.ops.object.*shape_key_*", "animation/shape_keys/shape_keys_panel.html"),
+	("bpy.ops.object.join_shapes*", "animation/shape_keys/shape_keys_panel.html"),
 	("bpy.ops.object.select_less*", "scene_layout/object/selecting.html#bpy-ops-object-select-less"),
 	("bpy.ops.object.select_more*", "scene_layout/object/selecting.html#bpy-ops-object-select-more"),
 	("bpy.ops.object.track_clear*", "animation/constraints/interface/adding_removing.html#bpy-ops-object-track-clear"),