adds atom.xml feed, simplifies authors metadata, adds description for release

[stockholmux]

Description

This release atom.xml adds a feed to valkey.io

Three things were needed & accomplished in this PR

1. generate_feed was set to true
2. The blog metadata needed to be reconfigured moving the authors array out from under extra back up to top-level of the meta data object. I had to touch all the blog posts to fix this and make a minor change the page template.
3. Add the feed auto discovery tag to the page header

To my pleasant surprise Zola was smart enough to find any page with a date and add it to the feed. Since releases are technically pages with dates, they are also included in the feed, not just blog posts. I imagine this will be very useful for folks. Because releases don't really have any content, the resulting atom entry was a bit mysterious. Consequently, I added a description to the 7.2.5 release. This doesn't show up in any other rendered state except the feed.

Issues Resolved

#79

Check List

• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the BSD-3-Clause License.

[bbarani]

@stockholmux Overall it looks good but we will face same issues as search index creation if we are planning to generate atom feed for topics / documentation (as they are not directly under the content folder rather placed via script) but this should work fine for blogs.

[stockholmux]

@bbarani Atom/XML feeds are only generated for content with a specified date.. None of the documentation has this property (and I don't think we'd do that).