Make the Atreus' keyscan interval more conservative by default to help smooth out perceived chatter issues with Speed Copper switches.

src/kaleidoscope/device/keyboardio/Atreus2.h

@@ -33,6 +33,8 @@ namespace keyboardio {
 struct AtreusProps : kaleidoscope::device::ATmega32U4KeyboardProps {
   struct KeyScannerProps : public kaleidoscope::driver::keyscanner::ATmegaProps {
 
+    static const uint16_t keyscan_interval = 2700;
+
     static constexpr uint8_t matrix_rows = 4;
     static constexpr uint8_t matrix_columns = 12;
     typedef MatrixAddr<matrix_rows, matrix_columns> KeyAddr;