docs(props): add long step prop

Author: marcocesarato

PROPS.md

@@ -41,6 +41,7 @@
 | `inputStyle`            | Input Style (Text number at middle)                                                                                            | Object           |                  | Could overwrite other props                      |
 | `inputProps`            | Customized TextInput Component props                                                                                           | Object           | `null`           |                                                  |
 | `leftButtonProps`       | Customized left button (Touchable Component) props                                                                             | Object           | `null`           |                                                  |
+| `longStep`              | Value to increment or decrement the current spinner value `onLongPress`                                                        | String<br>Number | `step`           |
 | `maxLength`             | Limits the maximum number of characters that can be entered.                                                                   | Number           |                  |                                                  |
 | `max`                   | Max number permitted                                                                                                           | String<br>Number | `null`           |                                                  |
 | `min`                   | Min value permitted                                                                                                            | String<br>Number | `0`              |                                                  |