Add PlatformIO and npm install

Author: Neil Enns

.devcontainer/devcontainer.json

@@ -31,14 +31,15 @@
 
 	// Add the IDs of extensions you want installed when the container is created.
 	"extensions": [
-		"ms-python.python"
+		"ms-python.python",
+		"platformio.platformio-ide"
 	],
 
 	// 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": "pip3 install --user -r requirements.txt",
+	"postCreateCommand": "npm install",
 
 	// Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
 	"remoteUser": "vscode"