chore: restructure examples into single-file and conf.d-method subdirs

examples/single-file/remotes.yaml  — original monolithic config
examples/conf.d-method/            — one yaml per remote (alpine, github, pypi)

docker-compose updated to mount from examples/single-file/.

examples/conf.d-method/github.yaml

@@ -0,0 +1,12 @@
+remotes:
+  github:
+    base_url: "https://github.com"
+    type: "remote"
+    package: "generic"
+    description: "GitHub releases and files"
+    immutable_patterns:
+      - "gruntwork-io/terragrunt/.*terragrunt_linux_amd64.*"
+      - "prometheus/node_exporter/.*/node_exporter-.*\\.linux-amd64\\.tar\\.gz$"
+    cache:
+      immutable_ttl: 0
+      mutable_ttl: 0