Update author metadata references in feed templates

Adjusts Atom and RSS layouts to use `.Site.Params.author` for name and email fields. Also removes several generated logo resources.

layouts/_default/list.atom.xml

@@ -18,7 +18,7 @@
 {{ print "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\"?>" | safeHTML }}
 {{- printf "<?xml-stylesheet href=\"/atom.xsl\" type=\"text/xsl\"?>" | safeHTML }}
 <feed xmlns="http://www.w3.org/2005/Atom" xmlns:webfeeds="http://webfeeds.org/rss/1.0">
-{{ with .Site.Author.name }}
+{{ with .Site.Params.author.name }}
   <author>
     <name>{{ . }}</name>
     <uri>{{ $.Site.BaseURL }}</uri>

layouts/_default/rss.xml

@@ -21,8 +21,8 @@
     <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>
-    <language>{{ site.Language.LanguageCode }}</language>{{ with .Site.Author.email }}
+    <language>{{ site.Language.LanguageCode }}</language>{{ with .Site.Params.author.email }}
-    <managingEditor>{{.}}{{ with $.Site.Author.name }} ({{.}}){{end}}</managingEditor>{{end}}{{ with .Site.Author.email }}
+    <managingEditor>{{.}}{{ with $.Site.Author.name }} ({{.}}){{end}}</managingEditor>{{end}}{{ with .Site.Params.author.email }}
     <webMaster>{{.}}{{ with $.Site.Author.name }} ({{.}}){{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 }}
@@ -34,7 +34,7 @@
       <title>{{ .Title }}</title>
       <link>{{ .Permalink }}</link>
       <pubDate>{{ .Date.Format "Mon, 02 Jan 2006 15:04:05 -0700" | safeHTML }}</pubDate>
-      {{ with .Site.Author.email }}<author>{{.}}{{ with $.Site.Author.name }} ({{.}}){{end}}</author>{{end}}
+      {{ with .Site.Params.Author.email }}<author>{{.}}{{ with $.Site.Author.name }} ({{.}}){{end}}</author>{{end}}
       <guid>{{ .Permalink }}</guid>
       {{ if eq $rssFeedDescription "summary"}}
       <description>{{ .Summary | html }}</description>