feat: support for additional devices (e.g. Kindle)

[bnussbau]

This PR adds more flexibility in terms of device dimensions, rotation and image format to support more devices (like trmnl-kindle).

Tested working with Kindle 10th Gen and these Device Settings:

• Width (px): 1400
• Height (px): 1100
• Rotate (°): 90
• Image Format: PNG 8-bit Grayscale Gray 256c

Instructions to modify the Kindle: https://github.com/usetrmnl/trmnl-kindle

Note: BYOS Laravel requires a mac adress in the header when calling the api/display port. Be sure to adapt the curl command like this

# 2) Fetch JSON metadata
  RESPONSE="$(
    curl -s \
      -H "access-token: $API_KEY" \
      -H "id: $MAC_ADDRESS" \                  # add a Mac Address (can be fake or real)
      -H "battery-voltage: $BATTERY_VOLTAGE" \
      -H "rssi: $RSSI" \
      -A "$USER_AGENT" \
      "${BASE_URL}/api/display"
  )"