Make init files copy metadata from folder.

Fixes #267.

rojo-test/serve-test-snapshots/serve_test__edit_init_subscribe.snap

@@ -0,0 +1,18 @@
+---
+source: rojo-test/src/serve_test.rs
+expression: "subscribe_response.intern_and_redact(&mut redactions, ())"
+---
+messageCursor: 1
+messages:
+  - added: {}
+    removed: []
+    updated:
+      - changedClassName: ~
+        changedMetadata: ~
+        changedName: ~
+        changedProperties:
+          Source:
+            Type: String
+            Value: "-- Edited contents"
+        id: id-2
+sessionId: id-1