v0.2.1

Bug fix release — auto_address pin conversion, multi-sensor example.

Fixed

• auto_address() now converts integer GPIO pins to board pin objects
  before passing to DigitalInOut (Blinka compatibility)
• Test updated to verify pin-object conversion

Added

• examples/vl53l0x_multi_sensor.py — multiple VL53L0X sensors via auto_address
• VL53L0X API section in README