Document soft-takeover on the mixer knobs and pitch fader

Author: dtavan

source/hardware/controllers/denon_mc3000.md

@@ -96,6 +96,12 @@ controller and the Denon MC3000 mapping:
 | {hwlabel}`SYNC` | Beat-syncs the deck. Hold past a short delay to enable continuous sync lock instead of a one-time sync. The LED lights while sync is active. |
 | {hwlabel}`SHIFT` + {hwlabel}`SYNC` | Toggles quantize for the deck. |
 
+:::{hint}
+{hwlabel}`LEVEL`, {hwlabel}`FILTER`, {hwlabel}`HI`, {hwlabel}`MID`,
+{hwlabel}`LOW`, and the pitch fader (see Deck Section below) use
+soft-takeover: turning the physical control has no effect until it
+reaches the value Mixxx is currently using, so there's no jump.
+:::
 ## Deck Section