Add rel attribute to links

[UppaJung]

Suggested by Adam Shostack

Add or rel="nofollow" to link in user comments so that there's less of an incentive for link spam.

https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/rel#nofollow

Interestingly, MDN writes

The nofollow relationship may indicate the current document's owner does not endorse the referenced document. It is often included by Search Engine Optimizers pretending their link farms are not spam pages.

[UppaJung]

fixed