Add devcontainer config

Author: martineckardt

.devcontainer/devcontainer.json

@@ -0,0 +1,11 @@
+// For format details, see https://aka.ms/devcontainer.json.
+{
+	"name": "Avalanche-Network-Runner Dev Container",
+
+	"image": "golang:latest",
+	"runArgs": ["--network=host"],
+
+	"remoteEnv": {
+		"PATH": "${containerEnv:PATH}:${containerWorkspaceFolder}/bin"
+	}
+}