Write and link implementation report

[mjwilson-google]

See https://www.w3.org/pubrules/doc/rules/?profile=CR#implReport
Since both Chromium and Firefox already have implementations, this should be possible to write now even though it may not be strictly necessary until we apply to advance to REC status.

[mjwilson-google]

WG 2023-10-05 conclusion: just make statement we don't have one for CR.

[mjwilson-google]

I'll close this and let the recommendation process drive the call for implementations and implementation report preparation.