Add devcontainer support for production-parity debugging

.devcontainer/devcontainer.json

@@ -0,0 +1,18 @@
+{
+  "dockerComposeFile": ["../docker-compose.yml", "docker-compose_extend.yml"],
+  "service": "web",
+  "name": "pkmntrade-club",
+  "workspaceFolder": "/workspace",
+  "postStartCommand": "direnv allow /workspace",
+  "remoteUser": "app",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-python.python",
+        "ms-python.black-formatter",
+        "ms-python.isort",
+        "ms-azuretools.vscode-docker"
+      ]
+    }
+  }
+}