Added dependency on debug package, converted console.log to debug logs

I find these console logs valuable for development but don't want them on all the time for everyone. It's cumbersome to comment/uncomment them continually, so this package helps nicely. I generally don't like adding dependencies, but this one seems wildly popular and itself only has one dependency (and that dependencies doesn't depend on anything else). So it seems acceptable to use.

I also enabled these debug logs by default when running the example configuration from VSCode.

.vscode/launch.json

@@ -11,7 +11,10 @@
             "program": "${workspaceFolder}/example.js",
             "skipFiles": [
                 "<node_internals>/**"
-            ]
+            ],
+            "env": {
+                "DEBUG": "sl:*"
+            }
         }
     ]
 }