spec(web): add jekyll website

spec/web/site/Gemfile

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+gem "jekyll-theme-chirpy", "~> 6.4", ">= 6.4.2"
+
+group :test do
+  gem "html-proofer", "~> 4.4"
+end
+
+# Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
+# and associated library.
+platforms :mingw, :x64_mingw, :mswin, :jruby do
+  gem "tzinfo", ">= 1", "< 3"
+  gem "tzinfo-data"
+end
+
+# Performance-booster for watching directories on Windows
+gem "wdm", "~> 0.1.1", :platforms => [:mingw, :x64_mingw, :mswin]
+
+# Lock `http_parser.rb` gem to `v0.6.x` on JRuby builds since newer versions of the gem
+# do not have a Java counterpart.
+gem "http_parser.rb", "~> 0.6.0", :platforms => [:jruby]