Add .devcontainer and update README.md

Author: mor10

.devcontainer/devcontainer.json

@@ -0,0 +1,22 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/typescript-node
+{
+	"name": "AgentGPT",
+	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+	"image": "mcr.microsoft.com/devcontainers/typescript-node:0-18"
+
+	// 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": "yarn install",
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}

README.md

@@ -69,6 +69,20 @@ More Coming soon...
 
 ## 👨‍🚀 Getting Started
 
+### 🚀 GitHub Codespaces
+
+The easiest way to run AgentGPT immediately is by using [GitHub Codespaces](https://github.com/features/codespaces).
+
+1. From the GitHub repo, click the green "Code" button and select "Codespaces".
+2. Create a new Codespace or select a previous one you've already created.
+3. Codespaces opens in a separate tab in your browser.
+4. In terminal, run `bash ./setup.sh --local`
+5. When prompted in terminal, add your OpenAI API key.
+6. Click "Open in browser" when the build process completes.
+
+- To shut AgentGPT down, enter Ctrl+C in Terminal.
+- To restart AgentGPT, run `npm run dev` in Terminal.
+
 ### 🐳 Docker Setup
 
 The easiest way to run AgentGPT locally is by using docker.