Curate JSON-Feed topic

[trvny]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• This change is not self-promotion.

Which change are you proposing?

• Suggesting edits to an existing topic or collection
• Curating a new topic or collection
• Something that does not neatly fit into the binary options above

Curating a new topic or collection

• I've formatted my changes as a new folder directory, named for the topic as it appears in the GitHub topic URL.
• My folder contains a square 288x288 PNG image and index.md.
• All required fields in my index.md conform to the Style Guide and API docs.

JSON Feed is an established web syndication format with a public specification and open source implementations. This adds concise metadata, official links, related topics, and a square topic image.

[github-actions]

Maintainer triage

Topics

• json-feed — 114 repositories — topic page