Readme update for proposed hasTouch prop.

hasTouch documentarion + update 'Bool' on 'locked' for boolean consistency.

Author: irfaan

README.md

@@ -149,7 +149,8 @@ module.exports = CustomTabBar;
   be able to animate itself along with the tab content.
 - **`onChangeTab`** _(Function)_ - function to call when tab changes, should accept 1 argument which is an Object containing two keys: `i`: the index of the tab that is selected, `ref`: the ref of the tab that is selected
 - **`edgeHitWidth`** _(Integer)_ - region (in pixels) from the left & right edges of the screen that can trigger swipe. Default is 30, which is the same as the swipe-back gesture on iOS.
-- **`locked`** _(boolean)_ - dynamically disable scrolling between tabs.
+- **`hasTouch`** _(Function)_ - returns `true` when ScrollableTabView starts being panned and `false` when it is released. Not triggered when `locked` (Bool) is true.
+- **`locked`** _(Bool)_ - dynamically disable scrolling between tabs.
 - **`springTension`** _(Integer)_ - a number between `1` and `100`, controls the amount of tension on the spring that guides the scroll animation - see [example](http://facebook.github.io/rebound-js/examples/#graph-canvas).
 - **`springFriction`** _(Integer)_ - a number between `1` and `30`, controls the amount of friction on the spring that guides the scroll animation - see [example](http://facebook.github.io/rebound-js/examples/#graph-canvas).
 - **`clampSpring`** _(Bool)_ - if `true`, the spring will not bounce at all - if `false`, it will oscillate around the target value before settling.