fix launch.json

.vscode/launch.json

@@ -4,14 +4,31 @@
   // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
   "version": "0.2.0",
   "configurations": [
+    {
+      "type": "firefox",
+      "request": "attach",
+      "name": "Attach",
+      "pathMappings": [
+        {
+          "url": "webpack:///ext",
+          "path": "${workspaceFolder}/src/ext"
+        }
+      ]
+    },
     {
       "name": "Launch addon",
       "type": "firefox",
       "request": "launch",
-            "port":6000,
+      "port": 6000,
       "reAttach": true,
       "addonType": "webExtension",
       "addonPath": "${workspaceFolder}/dist-ff",
+      "pathMappings": [
+        {
+          "url": "webpack:///ext",
+          "path": "${workspaceFolder}/src/ext"
+        },
+      ]
     }
   ],
   "firefox": {