Add CODEOWNERS file (#2420)

* Add CODEOWNERS file

This makes it very clear when you're stepping down from the post as a maintainer, and makes it clear for users who is expected to review their PR

* Fix grammar

* Make @kchibisov receive pings for the X11 platform

* Fix typo

Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

.github/CODEOWNERS

@@ -0,0 +1,35 @@
+# Core maintainers:
+# - @msiglreith
+# - @kchibisov
+# - @madsmtm
+# - @maroider
+
+# Android
+/src/platform/android.rs            @msiglreith
+/src/platform_impl/android          @msiglreith
+
+# iOS
+/src/platform/ios.rs                @francesca64
+/src/platform_impl/ios              @francesca64
+
+# Unix in general
+/src/platform/unix.rs               @kchibisov
+/src/platform_impl/linux/mod.rs     @kchibisov
+
+# Wayland
+/src/platform_impl/linux/wayland    @kchibisov
+
+# X11
+/src/platform_impl/linux/x11        @kchibisov
+
+# macOS
+/src/platform/macos.rs              @madsmtm
+/src/platform_impl/macos            @madsmtm
+
+# Web (no maintainer)
+/src/platform/web.rs
+/src/platform_impl/web
+
+# Windows
+/src/platform/windows.rs            @msiglreith
+/src/platform_impl/windows          @msiglreith

CONTRIBUTING.md

@@ -44,10 +44,9 @@ Once your PR is deemed ready, the merging maintainer will take care of resolving
 
 ## Maintainers & Testers
 
-The current [list of testers and contributors](https://github.com/rust-windowing/winit/wiki/Testers-and-Contributors)
-can be found on the Wiki.
+The current maintainers are listed in the [CODEOWNERS](.github/CODEOWNERS) file.
 
-If you are interested in contributing or testing on a platform, please add yourself to that table!
+If you are interested in being pinged when testing is needed for a certain platform, please add yourself to the [Testers and Contributors](https://github.com/rust-windowing/winit/wiki/Testers-and-Contributors) table!
 
 ## Making a new release
 

HALL_OF_CHAMPIONS.md

@@ -15,9 +15,12 @@ future endeavors:
   vastly more sustainable era of winit.
 * [@goddessfreya]: For selflessly taking over maintainership of glutin, and her
   stellar dedication to improving both winit and glutin.
+* [@ArturKovacs]: For consistently maintaining the macOS backend, and his
+  immense involvement in designing and implementing the new keyboard API.
 
 [@tomaka]: https://github.com/tomaka
 [@vberger]: https://github.com/vberger
 [@francesca64]: https://github.com/francesca64
 [@Osspial]: https://github.com/Osspial
 [@goddessfreya]: https://github.com/goddessfreya
+[@ArturKovacs]: https://github.com/ArturKovacs