Exclude content frorm RSS feed

[racehd]

Hello,

While reviewing the frontmatter docs I found there is an xml param that controls whether or not a page is featured in the sitemap.xml, however, the rss.xml currently has no logic to exclude content from it using this xml param.

Here are a few options:

1. Add functionality to rss.xml to exclude pages that have xml: true. Code can be found in 🐛 Fix(rss.xml): Add missing xml frontmatter logic #2433 to achieve this. There is some risk where users may have intended to have something in the RSS feed (index.xml) but not the sitemap.xml.
2. Add a separate frontmatter param, such as excludeFromRSS which would be specific to excluding from the rss.xml. This gives more granular control which xml file the page is being excluded from.
3. Same as 2, but the xml param could be renamed to excludeFromSitemap while still leaving the old xml param functional to prevent breaking anyone's site for the time being.
4. Do nothing. Technically base hugo already allows excluding from RSS since the rss.xml references RegularPages. By using the build.list: never then the page is removed from all collections (lists / RegularPages) and would be excluded from rss feed. The downsides to this could be that there might be pages someone wants included in lists but they do not want it in the RSS feed.

I am in favor or 2/3, but please let me know your thoughts. Thanks kindly