Update docs

docs/api-reference/deck.md

@@ -154,29 +154,31 @@ Extra pixels around the pointer to include while picking. This is helpful when r
 
 #### `getTooltip` (Function, optional)
 
-Function that takes a hovered-over point and displays a tooltip. 
+Callback that takes a hovered-over point and renders a tooltip. If the prop is not specified, the tooltip is hidden.
 
-If the function returns `null`, the tooltip is hidden, with the CSS `display` property set to `none`.
-If the function returns a string, that string is rendered in a tooltip with the default CSS styling described below.
-Otherwise, the function can return an object with the following fields:
+Callback arguments:
+
+* `info` - the [picking info](/docs/developer-guide/interactivity.md#the-picking-info-object) describing the object being hovered.
+
+If the callback returns `null`, the tooltip is hidden, with the CSS `display` property set to `none`.
+If the callback returns a string, that string is rendered in a tooltip with the default CSS styling described below.
+Otherwise, the callback can return an object with the following fields:
 
 * `text` (String, optional) - Specifies the `innerText` attribute of the tooltip.
 * `html` (String, optional) - Specifies the `innerHTML` attribute of the tooltip. Note that this will override the specified `innerText`.
-* `className` (String, optional) - Class name to attach to the tooltip element.
+* `className` (String, optional) - Class name to attach to the tooltip element. The element has the default class name of `deck-tooltip`.
 * `style` (Object, optional) - An object of CSS styles to apply to the tooltip element, which can override the default styling.
 
 By default, the tooltip has the following CSS style:
 
 ```css
 z-index: 1;
-position: 'absolute';
+position: absolute;
 color: #a0a7b4;
 background-color: #29323c;
 padding: 10px;
 ```
 
-The element also has the default class name of `deck-tooltip`.
-
 ##### `useDevicePixels` (Boolean, optional)
 
 When true, device's full resolution will be used for rendering, this value can change per frame, like when moving windows between screens or when changing zoom level of the browser.