Fix cuRobo page discoverability and filename hygiene

Author: nevalsar

_data/navigation.yml

@@ -345,6 +345,8 @@ wiki:
         url: /wiki/planning/frenet-frame-planning.md/
       - title: Move Base Flex
         url: /wiki/planning/move-base-flex/
+      - title: Manipulator Trajectory Planning using CuRoBo
+        url: /wiki/planning/curobo-trajectory-planning/
 # Main links appear in the header.
 main:
   - title: Wiki

…i/planning/curobo_trajectory_planning.md …i/planning/curobo-trajectory-planning.mdwiki/planning/curobo_trajectory_planning.md renamed to wiki/planning/curobo-trajectory-planning.md wiki/planning/curobo_trajectory_planning.md renamed to wiki/planning/curobo-trajectory-planning.md

@@ -4,3 +4,6 @@ title: Planning
 ---
 **This page is a stub.** You can help us improve it by [editing it](https://github.com/RoboticsKnowledgebase/roboticsknowledgebase.github.io).
 {: .notice--warning}
+
+## Articles
+- [Manipulator Trajectory Planning using CuRoBo](/wiki/planning/curobo-trajectory-planning/)