Add LED tool: device, CLI, web UI, build scripts, and tests

- device.py: device communication/handling
- cli.py: CLI interface updates
- web.py: web interface
- build.py, build.sh, install.sh: build and install scripts
- Pipfile: Python dependencies
- lib/mpremote: mpremote library
- test_*.py: import and LED tests
- Updated .gitignore and README

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/mpremote/__init__.py

@@ -0,0 +1 @@
+# Empty __init__.py to make this a package