Migrate state

.env.example

@@ -7,3 +7,9 @@ RAILWAY_API_TOKEN=
 # Cloudflare API token for the aerlinn.net DNS records: Zone.DNS Edit and
 # Zone.Zone Read, on that zone only.
 CLOUDFLARE_API_TOKEN=
+
+# Keys for the tfstate bucket on Railway, where every project's Terraform state
+# lives: `railway bucket credentials` in the tfstate project, or the bucket's
+# Credentials tab in the dashboard.
+TFSTATE_ACCESS_KEY_ID=
+TFSTATE_SECRET_ACCESS_KEY=