feat: add devcontainer for deployment

.devcontainer/devcontainer.json

@@ -0,0 +1,12 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/universal
+{
+  "name": "Piperchat",
+  // Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+  "image": "mcr.microsoft.com/devcontainers/universal:2-linux",
+
+  // Use 'forwardPorts' to make a list of ports inside the container available locally.
+  "forwardPorts": [80],
+
+  "postStartCommand": "cp .env.template .env && ./deploy.sh"
+}