docs: Clarify directory upload option in README.md to include 'nonClick' support

Author: linhf123

README.md

@@ -70,7 +70,7 @@ React.render(<Upload />, container);
 |component | "div"|"span" | "span"| wrap component name |
 |action| string &#124; function(file): string &#124; Promise&lt;string&gt; | | form action url |
 |method | string | post | request method |
-|directory| boolean | false | support upload whole directory |
+|directory| boolean \| 'nonClick' | false | support upload whole directory, 'nonClick' means unSupport click to upload directory |
 |data| object/function(file) | | other data object to post or a function which returns a data object(a promise object which resolve a data object) |
 |headers| object | {} | http headers to post, available in modern browsers |
 |accept | string | | input accept attribute |