Update services landing page; remove motion next-steps section

- Services _index.md: add motion card, update description to mention
  service APIs link
- Motion _index.md: remove tutorial-linking "Next steps" section
  (reference pages should not link to tutorials)

SLAM card to be added after PR #4977 merges.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: shannonbradshaw

docs/reference/services/_index.md

@@ -9,8 +9,9 @@ description: "Configuration reference for Viam built-in services: per-service mo
 date: "2026-04-14"
 ---
 
-Configuration reference for Viam built-in services. For API method reference, see [APIs](/reference/apis/).
+Configuration reference for Viam built-in services. Each page covers available models, configuration attributes, and JSON templates. For API method reference, see [Service APIs](/reference/apis/services/).
 
 {{< cards >}}
 {{% card link="/reference/services/vision/" %}}
+{{% card link="/reference/services/motion/" %}}
 {{< /cards >}}

docs/reference/services/motion/_index.md

@@ -172,11 +172,3 @@ The `plan_deviation_m` for `MoveOnMap()` on calls issued from the **CONTROL** ta
 
 {{< /alert >}}
 
-## Next steps
-
-The following tutorials contain complete example code for interacting with a robot arm through the arm component API, and with the motion service API, respectively:
-
-{{< cards >}}
-{{% card link="/motion-planning/move-an-arm/move-to-pose/" %}}
-{{% card link="/tutorials/services/plan-motion-with-arm-gripper" %}}
-{{< /cards >}}