XR interface is actually standards track (#4963)
XR interface is actually standards track (#4963)

Fix the `XR` interface to be denoted as being
on the standards track, rather than not. Oops.

Source: https://immersive-web.github.io/webxr
mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data