[Docs] Document Touchable hover callbacks

## Description

Documents `onHoverIn`/`onHoverOut` on the `Touchable` page, together
with the behaviour that isn't obvious from the signature: how the two
pair up, what `disabled` does to an open hover, which platforms report
the crossings during a press, tvOS driving hover from focus, and hover
state not surviving an unmount or a detach.

## Test plan

`yarn start` in `packages/docs-gesture-handler`.

Author: j-piasecki

packages/docs-gesture-handler/docs/components/touchable.mdx

@@ -455,6 +455,74 @@ onLongPress?: () => void;
 
 Triggered when the button gets pressed for at least [`delayLongPress`](#delaylongpress) milliseconds.
 
+### onHoverIn
+
+<CollapsibleCode 
+label="Show composed types definitions"
+expandedLabel="Hide composed types definitions"
+lineBounds={[0, 1]}
+src={`
+onHoverIn?: (e: ButtonEvent) => void;
+
+type ButtonEvent = {
+    pointerInside: boolean;
+    x: number;
+    y: number;
+    absoluteX: number;
+    absoluteY: number;
+    numberOfPointers: number;
+    pointerType: PointerType;
+}
+
+enum PointerType {
+    TOUCH,
+    STYLUS,
+    MOUSE,
+    KEY,
+    OTHER,
+}
+`}/>
+
+Triggered when a non-touch pointer — a mouse, a trackpad cursor, or a hovering stylus — moves over the button (analogous to `onHoverIn` in `Pressable` from RN core). Touch pointers never report hover.
+
+### onHoverOut
+
+<CollapsibleCode 
+label="Show composed types definitions"
+expandedLabel="Hide composed types definitions"
+lineBounds={[0, 1]}
+src={`
+onHoverOut?: (e: ButtonEvent) => void;
+
+type ButtonEvent = {
+    pointerInside: boolean;
+    x: number;
+    y: number;
+    absoluteX: number;
+    absoluteY: number;
+    numberOfPointers: number;
+    pointerType: PointerType;
+}
+
+enum PointerType {
+    TOUCH,
+    STYLUS,
+    MOUSE,
+    KEY,
+    OTHER,
+}
+`}/>
+
+Triggered when the hovering pointer leaves the button (analogous to `onHoverOut` in `Pressable` from RN core).
+
+The two callbacks are paired — an `onHoverIn` is followed by exactly one `onHoverOut` once the pointer leaves. Because hover is only reported while the button is not `disabled`, disabling a hovered button reports `onHoverOut`, and re-enabling it while the pointer is still inside reports `onHoverIn` again.
+
+On Android, iOS, and macOS the crossings are reported during a press as well: dragging a held pointer off the button and back on reports `onHoverOut` and `onHoverIn`, provided a hover was already open when the press started — which for a stylus needs hardware that reports stylus hover at all. On web nothing is reported while a stylus is in contact, because the browser captures the pointer for the duration of the press.
+
+On tvOS hover follows focus rather than a pointer. Focusing the button reports `onHoverIn` and moving focus away reports `onHoverOut`, with the event describing the center of the button and a `pointerType` of `OTHER`.
+
+Unmounting a hovered component does not report `onHoverOut` — the callback goes away with the component. On Android, iOS, and macOS the hover state is also not carried across a detach: if the component moves in the tree while hovered and lands away from the pointer, the pending `onHoverOut` is not delivered, and the next hover over it is treated as a continuation rather than a new `onHoverIn`, resynchronizing on the following `onHoverOut`. On web the component is rebuilt instead, so the next hover reports a fresh `onHoverIn`. Use these callbacks to drive presentation, not to hold state that has to be unwound.
+
 
 ### delayLongPress