Add link to egui-ash in README.md

Closes #3706

README.md

@@ -205,6 +205,7 @@ These are the official egui integrations:
 ### 3rd party integrations
 
 * [`amethyst_egui`](https://github.com/jgraef/amethyst_egui) for [the Amethyst game engine](https://amethyst.rs/).
+* [`egui-ash`](https://github.com/MatchaChoco010/egui-ash) for [`ash`](https://github.com/ash-rs/ash) (a very lightweight wrapper around Vulkan).
 * [`bevy_egui`](https://github.com/mvlabat/bevy_egui) for [the Bevy game engine](https://bevyengine.org/).
 * [`egui_glfw_gl`](https://github.com/cohaereo/egui_glfw_gl) for [GLFW](https://crates.io/crates/glfw).
 * [`egui_glium`](https://github.com/fayalalebrun/egui_glium) for compiling native apps with [Glium](https://github.com/glium/glium).