chore(dogfood): include multiple templates under dogfood/ (#16846)

* Renames `dogfood/contents` to `dogfood/coder`.
* Moves `coder-envbuilder` to `dogfood/coder-envbuilder`.
* Updates `dogfood/main.tf` to push `coder-envbuilder` template.
* Replaces hard-coded organization IDs with
`data.coderd_organization.default.id`.

.github/workflows/security.yaml

@@ -99,7 +99,7 @@ jobs:
           # version in the comments will differ. This is also defined in
           # ci.yaml.
           set -euxo pipefail
-          cd dogfood/contents
+          cd dogfood/coder
           mkdir -p /usr/local/bin
           mkdir -p /usr/local/include