Add deployment_configuration to make deployment using infra-rebuild work

Also document usage of infra-rebuild and its configuration file.

deployment_configuration.json

@@ -0,0 +1,28 @@
+{
+  "default": {
+    "targetUser": "colmena-deploy"
+  },
+  "hosts": {
+    "netbox": {
+      "targetHostname": "netbox-intern.hamburg.ccc.de"
+    },
+    "matrix": {
+      "targetHostname": "matrix-intern.hamburg.ccc.de"
+    },
+    "public-web-static": {
+      "targetHostname": "public-web-static-intern.hamburg.ccc.de"
+    },
+    "git": {
+      "targetHostname": "git.hamburg.ccc.de"
+    },
+    "forgejo-actions-runner": {
+      "targetHostname": "forgejo-actions-runner-intern.hamburg.ccc.de"
+    },
+    "eh22-wiki": {
+      "targetHostname": "eh22-wiki-intern.hamburg.ccc.de"
+    },
+    "nix-box-june": {
+      "targetHostname": "nix-box-june-intern.hamburg.ccc.de"
+    }
+  }
+}