fix: category page | set link to post to be relative

[treckstar]

In some instances, on the category page, the link will render as blog/blog/{slug} due to the link not being relative.

This will cause a bunch of random errors that are hard to debug. (i.e., no meta/SEO attributes found).

[PaulBratslavsky]

@treckstar thank you for the help 🙂