Update repo structure as part of nixification

puppet/production/hiera.yaml

@@ -1,11 +0,0 @@
----
-version: 5
-defaults:                # Used for any hierarchy level that omits these keys.
-  datadir   : hieradata       # This path is relative to hiera.yaml's directory.
-  data_hash : yaml_data  # Use the built-in YAML backend.
-
-hierarchy:
-  - name: "Per-node data"
-    path: "nodes/%{hostname}.yaml"
-  - name: "Common data"
-    path: "common.yaml"