Add devcontainer

.devcontainer/Dockerfile

@@ -0,0 +1,10 @@
+FROM dart
+
+RUN apt-get update
+RUN apt-get install -y curl git unzip xz-utils zip libglu1-mesa
+
+RUN apt-get clean
+
+RUN git clone https://github.com/flutter/flutter.git -b stable --depth 1 /flutter
+ENV PATH="/flutter/bin:$PATH"
+RUN flutter doctor

.devcontainer/devcontainer.json

@@ -0,0 +1,15 @@
+{
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
+  "forwardPorts": [3000],
+  "name": "Flutter",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "Dart-Code.dart-code",
+        "Dart-Code.flutter"
+      ]
+    }
+  }
+}