add devcontainer.json (#73)

.devcontainer/devcontainer.json

@@ -0,0 +1,20 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/go
+{
+  "name": "Go",
+  // Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+  "image": "mcr.microsoft.com/devcontainers/go:1-1.21-bullseye",
+  "features": {
+    "ghcr.io/devcontainers/features/go:1": {}
+  }
+  // Features to add to the dev container. More info: https://containers.dev/features.
+  // "features": {},
+  // Use 'forwardPorts' to make a list of ports inside the container available locally.
+  // "forwardPorts": [],
+  // Use 'postCreateCommand' to run commands after the container is created.
+  // "postCreateCommand": "go version",
+  // Configure tool-specific properties.
+  // "customizations": {},
+  // Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+  // "remoteUser": "root"
+}