Speed up frames and add key test sweeps

Drop the per-packet device.pause(1), which rounds up to the Windows timer tick
and capped the keyboard at roughly 10 fps; keep a pause in low frame-rate mode.
Add a "Key test" option with column and row sweeps to verify the LED map.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -8,6 +8,9 @@ product ID or have a K87 layout, so the keyboard is ignored without this plugin.
 
 Copy `Womier_K87_EVision.js` to `%USERPROFILE%\Documents\WhirlwindFX\Plugins\` and restart SignalRGB.
 
+The device settings have a "Key test" option (column or row sweep) to check the LED map,
+and "Low frame-rate mode" in case the keyboard drops frames at full speed.
+
 ## Protocol
 
 - HID interface 1, usage page `0xFF1C`, usage `0x92` (collection 4), 64-byte output reports.