Enhance CNCF observability challenge metadata

Added tags, level, categories, and prerequisite knowledge to the CNCF observability challenge index.

Signed-off-by: jamieplu <179417684+jamieplu@users.noreply.github.com>

Author: jamieplu

content/challenges/d011fd20-a3f5-4480-883b-dfb34321d168/cncf-observability-challenge-with/_index.md

@@ -5,4 +5,16 @@ banner: "jaeger-icon-black.svg"
 courses: 1
 weight: 2
 id: "79ef4658-bc1d-4768-9e8e-dea864d5590d"
+tags: [meshery, jaeger, cncf]
+level: "intermediate"
+categories: "platform"
+
+prerequisite_knowledge:
+
+  - title: "Access to Meshery"
+    children:
+      - title: "Self-hosted Meshery"
+        link: "https://docs.meshery.io/installation"
+      - title: "Meshery Playground"
+        link: "https://play.meshery.io"       
 ---