Fix section comments in darkfish

This is almost certainly the wrong way to do this.  But the lack of
section comments has been bugging me for years, and this was my first
attempt at figuring out why it is broken.  Maybe someone else can fix it
The Right Way, or give me some advice on how to do so myself...

lib/rdoc/context/section.rb

@@ -177,7 +177,7 @@ def marshal_load array
   # Parses +comment_location+ into an RDoc::Markup::Document composed of
   # multiple RDoc::Markup::Documents with their file set.
 
-  def parse
+  def parse _comment_location
     case @comments
     when String then
       super

lib/rdoc/generator/markup.rb

@@ -25,7 +25,7 @@ def as_href(from_path)
   # Handy wrapper for marking up this object's comment
 
   def description
-    markup @comment
+    markup @comment || @comments&.first
   end
 
   ##

lib/rdoc/generator/template/darkfish/class.rhtml

@@ -38,7 +38,7 @@
     </header>
     <%- end -%>
 
-    <%- if section.comment then -%>
+    <%- if section.comment || section.comments.any? then -%>
     <div>
       <%= section.description %>
     </div>

lib/rdoc/text.rb

@@ -95,6 +95,7 @@ def flush_left text
   # Requires the including class to implement #formatter
 
   def markup text
+    @store ||= @parent&.store
     if @store.rdoc.options
       locale = @store.rdoc.options.locale
     else