chore: add configuration recipes

recipes/sign/README.md

@@ -0,0 +1,13 @@
+# Sign
+
+This example uses generated key. It can be generated as:
+
+```shell
+gpg --full-generate-key
+gpg --export-secret-keys -a <...> > repository-sign.gpg
+```
+
+1. Setup repository named `ahriman-demo` with architecture `x86_64`.
+2. Sing repository database with the distributed key.
+3. Start service in daemon mode with periodic (once per day) repository update.
+4. Repository is available at `http://localhost:8080/repo`.