README.md: add link to Gallery Part 6

README.md

@@ -164,7 +164,8 @@ User screenshots:
 <br>[Gallery Part 2](https://github.com/ocornut/imgui/issues/539) (Feb 2016 to Aug 2016)
 <br>[Gallery Part 3](https://github.com/ocornut/imgui/issues/772) (Aug 2016 to Jan 2017)
 <br>[Gallery Part 4](https://github.com/ocornut/imgui/issues/973) (Jan 2017 to Aug 2017)
-<br>[Gallery Part 5](https://github.com/ocornut/imgui/issues/1269) (Aug 2017 onward)
+<br>[Gallery Part 5](https://github.com/ocornut/imgui/issues/1269) (Aug 2017 to Feb 2018)
+<br>[Gallery Part 6](https://github.com/ocornut/imgui/issues/1607) (Feb 2018 onward)
 <br>Also see the [Mega screenshots](https://github.com/ocornut/imgui/issues/1273) for an idea of the available features.
 
 Various tools