Problem: missing preview links requirements to a PR

[angelicawill]

Before, I remember it was a rule that PRs should include a link to the prototype preview before requesting a review. However, I can't find this requirement explicitly documented in the contribution guidelines.

[angelicawill]

@zolotokrylin @markholdex can you clarify if this is still a requirement? or else you can close this issue as unplanned, thanks!

[zolotokrylin]

Yes, it should be a requirement. Thanks for spotting it!