feat: add logging for the extension

and for the new command

src/vscode/superbol-vscode-platform/superbol_commands.ml

@@ -27,6 +27,9 @@ type t =
     handler: handler;
   }
 
+let extension_oc : Vscode.OutputChannel.t Lazy.t =
+  lazy (Vscode.Window.createOutputChannel ~name:"SuperBOL Studio Extension")
+
 let commands = ref []
 
 let command id handler =
@@ -35,19 +38,31 @@ let command id handler =
   command
 
 let _editor_action_findReferences =
-  command "superbol.editor.action.findReferences" @@ Instance
+  let command_name = "superbol.editor.action.findReferences"  in
+  command command_name @@ Instance
     begin fun _instance ~args ->
       match args with
       | [arg1; arg2] ->
         let uri = Uri.parse (Ojs.string_of_js arg1) () in
         let line = Ojs.get_prop_ascii arg2 "line" |> Ojs.int_of_js in
         let character = Ojs.get_prop_ascii arg2 "character" |> Ojs.int_of_js in
         let pos = Position.make ~line ~character in
+        let lazy oc = extension_oc in
+        let value = "Info: Performing "
+                    ^ command_name
+                    ^ " on file "
+                    ^ Ojs.string_of_js arg1
+                    ^ " at position "
+                    ^ (string_of_int line) ^ ":" ^ (string_of_int character) in
+        OutputChannel.appendLine oc ~value;
         let _ = Commands.executeCommand
             ~command:"editor.action.findReferences"
             ~args:[Uri.t_to_js uri; Position.t_to_js pos ]
         in ()
-      | _ -> ()
+      | _ ->
+        let lazy oc = extension_oc in
+        let value = "Warning: " ^ command_name ^ " requires 2 arguments" in
+        OutputChannel.appendLine oc ~value
     end
 
 let _restart_language_server =