Update and format config example

Also add dhall-json for testing json/yaml conversion

config.example.dhall

@@ -1,16 +1,26 @@
-{ mqtt_servers.default = { host = "1.2.3.4", user = Some "username", pass = Some
-"password" }
-, layers.default
-  =
-  { default_mapping = Mapping.Print "no mapping!"
-  , mappings =
-      let sometopic = "homeassistant/switch/something/set"
+let T = ./types.dhall
 
-      in  { key_0 =
-              Mapping.Trigger (Action.MQTTPub { topic = sometopic, payload = "ON" })
-          , key_1 =
-              Mapping.Trigger
-                (Action.MQTTPub { topic = sometopic, payload = "OFF" })
-          }
-  }
-}
+in  { mqtt_servers.default
+      =
+      { host = "1.2.3.4", user = Some "username", pass = Some "password" }
+    , layers.default
+      =
+      { default_mapping = T.Action.Print "no mapping!"
+      , mappings =
+          let sometopic = "homeassistant/switch/something/set"
+
+          in  { key_0 =
+                  T.Mapping.Trigger
+                    (T.Action.MQTTPub { topic = sometopic, payload = "ON" })
+              , key_1 =
+                  T.Mapping.Trigger
+                    (T.Action.MQTTPub { topic = sometopic, payload = "OFF" })
+              , key_2 =
+                  T.Mapping.TriggerMulti
+                    [ T.Action.Print "Doing a thing"
+                    , T.Action.MQTTPub
+                        { topic = "thing/foo/bar", payload = "boop" }
+                    ]
+              }
+      }
+    }

flake.nix

@@ -34,6 +34,7 @@
           buildInputs = with pkgs; [
             # Dhall (config) stuff
             dhall
+            dhall-json
             dhall-lsp-server
             # Rust!
             (rust-bin.stable.latest.default.override {