behaviors(hold-tap): Implement quick_tap_ms (TAPPING_FORCE_HOLD)

Tap-and-hold a hold-tap to hold the tap behavior so it can repeat.
After a tap, if the same key is pressed within `quick_tap_ms`, the
tap behavior is always picked.

This is useful for things like `&ht LSHFT BACKSPACE` where holding
the backspace is required.

Implements #288.

app/dts/bindings/behaviors/zmk,behavior-hold-tap.yaml

@@ -13,6 +13,9 @@ properties:
     required: true
   tapping_term_ms:
     type: int
+  quick_tap_ms:
+    type: int
+    default: -1
   flavor:
     type: string
     required: false