docs: add early access badge to devcontainers admin (#17937)

[preview](https://coder.com/docs/@dev-container-tweaks/admin/templates/extending-templates/devcontainers)

---------

Co-authored-by: EdwardAngert <17991901+EdwardAngert@users.noreply.github.com>

docs/admin/templates/extending-templates/devcontainers.md

@@ -122,3 +122,5 @@ resource "docker_container" "workspace" {
 ## Next Steps
 
 - [Dev Containers Integration](../../../user-guides/devcontainers/index.md)
+- [Working with Dev Containers](../../../user-guides/devcontainers/working-with-dev-containers.md)
+- [Troubleshooting Dev Containers](../../../user-guides/devcontainers/troubleshooting-dev-containers.md)

docs/manifest.json

@@ -506,7 +506,8 @@
 								{
 									"title": "Configure a template for dev containers",
 									"description": "How to use configure your template for dev containers",
-									"path": "./admin/templates/extending-templates/devcontainers.md"
+									"path": "./admin/templates/extending-templates/devcontainers.md",
+									"state": ["early access"]
 								},
 								{
 									"title": "Process Logging",