fix(rss): hide private/unlisted pages in RSS feed

modules/blox/layouts/rss.xml

@@ -2,6 +2,7 @@
 {{- /* Upstream Hugo bug - RSS dates can be in future: https://github.com/gohugoio/hugo/issues/3918 */ -}}
 {{- $page_context := cond .IsHome site . -}}
 {{- $pages := $page_context.RegularPages -}}
+{{- $pages = where $pages "Params.private" "!=" true -}}
 {{- $limit := site.Config.Services.RSS.Limit -}}
 {{- if ge $limit 1 -}}
   {{- $pages = $pages | first $limit -}}