update atom feed output

this should fix the warning i get usually

(WARN  found no layout file for "atom" for kind "section": You
should create a template file which matches Hugo Layouts Lookup
Rules for this combination.)

config/_default/config.toml

@@ -22,32 +22,70 @@ summaryLength = 0
 #[outputs]
 #  home = ["HTML", "RSS", "JSON"]
 
+# removed for now
+# [mediaTypes]
+#   [mediaTypes."application/atom"]
+#     suffixes     = ["xml"]
+#
+# [outputFormats.Atom]
+#   mediaType      = "application/atom"
+#   baseName       = "index"
+#   isPlainText    = false
+#
+# [outputFormats.HumansTXT]
+#   mediaType      = "text/plain"
+#   baseName       = "humans"
+#   isPlainText    = true
+#   notAlternative = true
+#
+# [outputFormats.Tootpick]
+#   mediaType      = "text/html"
+#   basename       = "tootpick"
+#   isPlainText    = false
+#   isHTML         = true
+#   notAlternative = true
+#
+# [outputs]
+#   home = [ "HTML", "Atom", "JSON", "HumansTXT", "Tootpick" ]
+#   page = ["HTML"]
+#   section = ["HTML", "Atom"]
+#   # taxonomyTerm = ["HTML"]
+#   taxonomy = ["HTML"]
+
+# https://discourse.gohugo.io/t/atom-and-json-feeds/13572
+disableKinds = ["RSS"]  # kick out RSS
+
 [mediaTypes]
-  [mediaTypes."application/atom"]
+  [mediaTypes."application/atom+xml"]
     suffixes = ["xml"]
 
-[outputFormats.Atom]
+
-  mediaType      = "application/atom"
+[outputFormats.HTML]
 baseName              = "index"
-  isPlainText    = false
+NoUgly                = true
 
-[outputFormats.HumansTXT]
-  mediaType      = "text/plain"
-  baseName       = "humans"
-  isPlainText    = true
-  notAlternative = true
 
-[outputFormats.Tootpick]
+[outputFormats.ATOM]
-  mediaType      = "text/html"
+MediaType             = "application/atom+xml"
-  basename       = "tootpick"
+BaseName              = "feed"
-  isPlainText    = false
+suffix                = "xml"
-  isHTML         = true
+IsHTML                = false
-  notAlternative = true
+IsPlainText           = false
+noUgly                = true
+Rel                   = "alternate"
+
+[outputFormats.JSON]
+MediaType             = "application/json"
+BaseName              = "feed"
+suffix                = "json"
+IsHTML                = false
+IsPlainText           = true
+noUgly                = false
+Rel                   = "alternate"
 
 [outputs]
-  home = [ "HTML", "Atom", "JSON", "HumansTXT", "Tootpick" ]
+home                  = [ "HTML", "ATOM", "JSON"]
+section               = [ "HTML",  ]
 page                  = [ "HTML" ]
-  section = ["HTML", "Atom"]
-  # taxonomyTerm = ["HTML"]
 taxonomy              = [ "HTML" ]
-
+taxonomyTerm          = [ "HTML" ]