bluetooth.conf: change the syntax for rules from Lua to JSON

src/config/wireplumber.conf.d/bluetooth.conf

@@ -173,12 +173,13 @@ monitor.bluetooth-midi.rules = [
 
   ## This rule example allows changing properties on all Bluetooth MIDI nodes.
   # {
-  #   matches = {
+  #   matches = [
+  #     ## Matches all bluez midi nodes.
   #     {
-  #       ## Matches all nodes.
-  #       { "node.name", "matches", "bluez_midi.*" },
-  #     },
-  #   },
+  #       ## Matches all sources.
+  #       node.name = "~bluez_midi*"
+  #     }
+  #   ]
   #   update-props = {
   #     node.nick = "My Node"
   #     priority.driver = 100