Document swap-hands tap-toggle feature (#15229)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: filterpaper <filterpaper@localhost>

docs/feature_swap_hands.md

@@ -27,5 +27,7 @@ Note that the array indices are reversed same as the matrix and the values are o
 |`SH_MON`   |Swaps hands when pressed, returns to normal when released (momentary).   |
 |`SH_MOFF`  |Momentarily turns off swap.                                              |
 |`SH_TG`    |Toggles swap on and off with every key press.                            |
-|`SH_TT`    |Toggles with a tap; momentary when held.                                 |
+|`SH_TT`    |Momentary swap when held, toggles with repeated taps (see below).        |
 |`SH_OS`    |One shot swap hands: toggles while pressed or until next key press.      |
+
+`SH_TT` swap-hands tap-toggle key is similar to [layer tap-toggle](feature_layers.md?id=switching-and-toggling-layers). Tapping repeatedly (5 taps by default) will toggle swap-hands on or off, like `SH_TG`. Tap-toggle count can be changed by defining a value for `TAPPING_TOGGLE`.