Depth estimation task guide (#22205)

* added doc to toc, auto tip with  supported models, mention of task guide in model docs

* make style

* removed "see also"

* minor fix

docs/source/en/_toctree.yml

@@ -85,6 +85,8 @@
       title: Zero-shot object detection
     - local: tasks/zero_shot_image_classification
       title: Zero-shot image classification
+    - local: tasks/monocular_depth_estimation
+      title: Depth estimation
     title: Computer Vision
   - sections:
     - local: tasks/image_captioning