refactor: Add format on save for VS Code

Added settings to format various file types on save in VS Code.

Added some recommended VS Code extensions:

- Prettier for formatting various file types
- Python for formatting Python files
- C/C++ for formatting C files
- Devicetree for syntax highlighting
- CMake for syntax highlighting

.vscode/extensions.json

@@ -0,0 +1,9 @@
+{
+  "recommendations": [
+    "esbenp.prettier-vscode",
+    "ms-python.python",
+    "ms-vscode.cpptools",
+    "plorefice.devicetree",
+    "twxs.cmake"
+  ]
+}