docs: VSCode debug config

CONTRIBUTING.md

@@ -67,6 +67,32 @@ When you send a PR, make sure that:
 * You make the PR on the same branch you based your changes on. If you see commits
   that you did not make in your PR, you're doing it wrong.
 
+### Configuring VSCode
+
+### Configuring VSCode
+
+`.vscode/launch.json`:
+
+```json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch the hub",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${fileDirname}/..",
+            "env": {
+                "MERCURE_PUBLISHER_JWT_KEY": "!ChangeMe!",
+                "MERCURE_SUBSCRIBER_JWT_KEY": "!ChangeMe!"
+            },
+            "args": ["run", "-config", "Caddyfile.dev"]
+        }
+    ]
+}
+```
+
 ### Finding Deadlocks
 
 To debug potential deadlocks: