Fix documentation for scrollResponderScrollNativeHandleToKeyboard

Summary:
I'm pretty sure this is supposed to be "bottom" as opposed to "top", as it's the offset from the keyboard, which is at the bottom of the screen.
Closes facebook#11446

Differential Revision: D4339957

Pulled By: lacker

fbshipit-source-id: 62dca544a0167704d76cd972c44570f277ea63aa

Libraries/Components/ScrollResponder.js

@@ -436,7 +436,7 @@ var ScrollResponderMixin = {
    * parent view. Note that any module using this mixin needs to return
    * the parent view's ref in getScrollViewRef() in order to use this method.
    * @param {any} nodeHandle The TextInput node handle
-   * @param {number} additionalOffset The scroll view's top "contentInset".
+   * @param {number} additionalOffset The scroll view's bottom "contentInset".
    *        Default is 0.
    * @param {bool} preventNegativeScrolling Whether to allow pulling the content
    *        down to make it meet the keyboard's top. Default is false.