Add rel="noreferrer" to external links in pretty-feed-v3.xsl

[andreilgeorgescu]

This prevents potential security vulnerabilities.

This is unlikely to be an issue since the website being linked to is presumably controlled by the same person creating the RSS feed. However, it is still best practice to add rel="noreferrer" just to be safe.

Commonly, you might see noopener added in as well but noreferrer already includes nooepener implicitly so that would be redundant.

[ghost]

I would only apply noopener. First, it's the only one required for security reasons. Second, it makes more sense for site owners themselves to decide whether to send referrer headers using the document’s Referrer-Policy header.

[ghost]

Chrome treats target="_blank" as implying rel="noopener" by default. https://chromestatus.com/feature/6140064063029248