Updated typo in flexGrow functionality (#3694)

Author: ugouhar

docs/flexbox.md

@@ -1697,7 +1697,7 @@ export default FlexWrapLayout;
 
 - [`flexBasis`](layout-props#flexbasis) is an axis-independent way of providing the default size of an item along the main axis. Setting the `flexBasis` of a child is similar to setting the `width` of that child if its parent is a container with `flexDirection: row` or setting the `height` of a child if its parent is a container with `flexDirection: column`. The `flexBasis` of an item is the default size of that item, the size of the item before any `flexGrow` and `flexShrink` calculations are performed.
 
-- [`flexGrow`](layout-props#flexgrow) describes how any space within a container should be distributed among its children along the main axis. After laying out its children, a container will distribute any remaining space according to the flex grow values specified by its children.
+- [`flexGrow`](layout-props#flexgrow) describes how much space within a container should be distributed among its children along the main axis. After laying out its children, a container will distribute any remaining space according to the flex grow values specified by its children.
 
   `flexGrow` accepts any floating point value >= 0, with 0 being the default value. A container will distribute any remaining space among its children weighted by the children’s `flexGrow` values.