Theme: Update RSS template to hugo v0.134.3

Deprecation checks let the template break in some later release.

Patches:
- Add authors
- Use content instead of summary
- ~~use publish date instead of date~~ (in default template already

themes/ccchh/layouts/_default/rss.xml

@@ -1,4 +1,3 @@
-{{- /* Deprecate site.Author.email in favor of site.Params.author.email */}}
 {{- $authorEmail := "" }}
 {{- with site.Params.author }}
   {{- if reflect.IsMap . }}
@@ -6,14 +5,8 @@
       {{- $authorEmail = . }}
     {{- end }}
   {{- end }}
-{{- else }}
-  {{- with site.Author.email }}
-    {{- $authorEmail = . }}
-    {{- warnf "The author key in site configuration is deprecated. Use params.author.email instead." }}
-  {{- end }}
 {{- end }}
 
-{{- /* Deprecate site.Author.name in favor of site.Params.author.name */}}
 {{- $authorName := "" }}
 {{- with site.Params.author }}
   {{- if reflect.IsMap . }}
@@ -23,11 +16,6 @@
   {{- else }}
     {{- $authorName  = . }}
   {{- end }}
-{{- else }}
-  {{- with site.Author.name }}
-    {{- $authorName = . }}
-    {{- warnf "The author key in site configuration is deprecated. Use params.author.name instead." }}
-  {{- end }}
 {{- end }}
 
 {{- $pctx := . }}
@@ -48,12 +36,12 @@
     <title>{{ if eq .Title .Site.Title }}{{ .Site.Title }}{{ else }}{{ with .Title }}{{ . }} on {{ end }}{{ .Site.Title }}{{ end }}</title>
     <link>{{ .Permalink }}</link>
     <description>Recent content {{ if ne .Title .Site.Title }}{{ with .Title }}in {{ . }} {{ end }}{{ end }}on {{ .Site.Title }}</description>
-    <generator>Hugo -- gohugo.io</generator>
+    <generator>Hugo</generator>
-    {{ with $authorEmail }}
+    <language>{{ site.Language.LanguageCode }}</language>{{ with $authorEmail }}
     <managingEditor>{{.}}{{ with $authorName }} ({{ . }}){{ end }}</managingEditor>{{ end }}{{ with $authorEmail }}
     <webMaster>{{ . }}{{ with $authorName }} ({{ . }}){{ end }}</webMaster>{{ end }}{{ with .Site.Copyright }}
     <copyright>{{ . }}</copyright>{{ end }}{{ if not .Date.IsZero }}
-    <lastBuildDate>{{ .Date.Format "Mon, 02 Jan 2006 15:04:05 -0700" | safeHTML }}</lastBuildDate>{{ end }}
+    <lastBuildDate>{{ (index $pages.ByLastmod.Reverse 0).Lastmod.Format "Mon, 02 Jan 2006 15:04:05 -0700" | safeHTML }}</lastBuildDate>{{ end }}
     {{- with .OutputFormats.Get "RSS" }}
     {{ printf "<atom:link href=%q rel=\"self\" type=%q />" .Permalink .MediaType | safeHTML }}
     {{- end }}
@@ -69,7 +57,7 @@
       <pubDate>{{ .PublishDate.Format "Mon, 02 Jan 2006 15:04:05 -0700" | safeHTML }}</pubDate>
       {{- with $authorEmail }}<author>{{ . }}{{ with $authorName }} ({{ . }}){{ end }}</author>{{ end }}
       <guid>{{ .Permalink }}</guid>
-      <description>{{ .Content | html }}</description>
+      <description>{{ .Content | transform.XMLEscape | safeHTML }}</description>
     </item>
     {{- end }}
   </channel>