Configure an ansible playbook (#5)

* Configure an ansible playbook
to copy all required configurations to a Poseidon host.

* Copy also all TLS certificates if configured

* Exclude playbook in its own repository

* Adjust security.md to our current recommendations

* Add certificate generation and deployment

* Move access policy example file to the resources folder

docs/resources/server.example.hcl

@@ -0,0 +1,14 @@
+server {
+    enabled = true
+    bootstrap_expect = 2
+    server_join {
+        retry_join = ["<<other servers domain>>"]
+        retry_max = 3
+        retry_interval = "15s"
+    }
+
+    # https://www.nomadproject.io/docs/configuration/server
+    default_scheduler_config {
+        scheduler_algorithm = "spread"
+    }
+}