[DOC] Make Obs as Code docs public (#104843)

Co-authored-by: Isabel Matwawana <isabel.matwawana@grafana.com>

docs/sources/observability-as-code/_index.md

@@ -1,9 +1,4 @@
 ---
-_build:
-  list: false
-noindex: true
-cascade:
-  noindex: true
 description: Overview of Observability as Code including description, key features, and explanation of benefits.
 keywords:
   - observability