Fix documentation contribution link

docs/index.html

@@ -31,7 +31,7 @@
         var footer = [
           '<hr/>',
           '<footer class="Test">',
-          `<span>Caught a mistake or want to contribute to the documentation? <a href="https://github.com/wix/react-native-navigation/docs" target="_blank">Edit documentation on Github!</a>.</span>`,
+          `<span>Caught a mistake or want to contribute to the documentation? <a href="https://github.com/wix/react-native-navigation/tree/master/docs" target="_blank">Edit documentation on Github!</a>.</span>`,
           '</footer>'
         ].join('')
 
@@ -46,4 +46,4 @@
 <script src="//unpkg.com/docsify/lib/plugins/search.js"></script>
 <script src="//unpkg.com/docsify/lib/plugins/emoji.js"></script>
 <script src="//unpkg.com/docsify/lib/plugins/ga.js"></script>
-</html>
+</html>