Update README.md

Add link to v1.0.0-alpha.1 (Bootstrap4)

Author: DimaSavchenko

README.md

@@ -1,8 +1,9 @@
 Awesome Bootstrap Checkbox
 ==========================
-
 [Font Awesome][] [Bootstrap][] Checkboxes & Radios plugin. Pure CSS way to make inputs look prettier. **No Javascript!**
 
+We have [new version][] with support [Bootstrap 4][].
+
 **[Demo][]**
 
 Use
@@ -171,6 +172,8 @@ Based on the [Official Bootstrap Sass port][Bootstrap Sass] and the awesome [Fon
 
 [Demo]: http://flatlogic.github.io/awesome-bootstrap-checkbox/demo/
 [Bootstrap]: http://getbootstrap.com/
+[Bootstrap 4]: https://v4-alpha.getbootstrap.com/
+[new version]: https://github.com/flatlogic/awesome-bootstrap-checkbox/releases/tag/v1.0.0-alpha.1
 [Bootstrap Sass]: https://github.com/twbs/bootstrap-sass
 [Font Awesome]: https://github.com/FortAwesome/Font-Awesome
 [Glyphicons]: http://getbootstrap.com/components/#glyphicons