The open source OpenXR runtime

doc: Document !1951

+7
+1
doc/changes/compositor/mr.1951.md
··· 1 + multi: Add stub set thread hint function.
+1
doc/changes/ipc/mr.1951.md
··· 1 + Add support for thread hint function.
+1
doc/changes/state_trackers/mr.1951.md
··· 1 + OpenXR: Implementation of XR_KHR_android_thread_settings.
+4
doc/changes/xrt/mr.1951.md
··· 1 + Add `xrt_thread_hint` enum and `xrt_compositor::set_thread_hint` function, this 2 + function lets us implement the 3 + [XR_KHR_android_thread_settings](https://registry.khronos.org/OpenXR/specs/1.0/man/html/XR_KHR_android_thread_settings.html) 4 + extension.