asciidoctor-with-extensions: init asciidoctor-reducer at 1.0.5

Add asciidoctor-reducer to the extension list of asciidoctor.

pkgs/tools/typesetting/asciidoctor-with-extensions/Gemfile

···
 gem 'asciidoctor-mathematical'
 gem 'asciidoctor-multipage'
 gem 'asciidoctor-pdf'
+gem 'asciidoctor-reducer'
 gem 'asciidoctor-revealjs'
 gem 'coderay'
 gem 'pygments.rb'

pkgs/tools/typesetting/asciidoctor-with-extensions/Gemfile.lock

···
       prawn-table (~> 0.2.0)
       prawn-templates (~> 0.1.0)
       treetop (~> 1.6.0)
+    asciidoctor-reducer (1.0.5)
+      asciidoctor (~> 2.0)
     asciidoctor-revealjs (5.0.1)
       asciidoctor (>= 2.0.0, < 3.0.0)
     asciimath (2.0.5)
···
   asciidoctor-mathematical
   asciidoctor-multipage
   asciidoctor-pdf
+  asciidoctor-reducer
   asciidoctor-revealjs
   coderay
   pygments.rb

pkgs/tools/typesetting/asciidoctor-with-extensions/default.nix

···
     "asciidoctor-epub3"
     "asciidoctor-multipage"
     "asciidoctor-pdf"
+    "asciidoctor-reducer"
     "asciidoctor-revealjs"
   ];
 

pkgs/tools/typesetting/asciidoctor-with-extensions/gemset.nix

···
     };
     version = "2.3.9";
   };
+  asciidoctor-reducer = {
+    dependencies = ["asciidoctor"];
+    groups = ["default"];
+    platforms = [];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1708fi4bxjpkdszm6a4naa0qcsl0vqnhcklryn2sysl24zaz07h5";
+      type = "gem";
+    };
+    version = "1.0.5";
+  };
   asciidoctor-revealjs = {
     dependencies = ["asciidoctor"];
     groups = ["default"];