Merge pull request #1429 from projectblacklight/document_heading

Re-add deprecated #document_heading method to the show presenter

app/presenters/blacklight/show_presenter.rb

@@ -1,6 +1,9 @@
 # frozen_string_literal: true
 module Blacklight
   class ShowPresenter
+    extend Deprecation
+    self.deprecation_horizon = 'Blacklight version 7.0.0'
+
     # @param [SolrDocument] document
     # @param [ActionController::Base] controller scope for linking and generating urls
     # @param [Blacklight::Configuration] configuration
@@ -53,6 +56,12 @@ def heading
       field_values(field_config(f), value: @document[f])
     end
 
+    # @deprecated
+    def document_heading
+      heading
+    end
+    deprecation_deprecate document_heading: "replaced by #heading"
+
     ##
     # Render the show field value for a document
     #