Add gems for smoother installation

Gemfile

@@ -1,2 +1,13 @@
 source "https://rubygems.org"
 gemspec
+
+# Extra optional dependencies so it works better out of the box regardless of the runtime environment
+
+# Default Jekyll markdown parser it should already be installed
+gem "kramdown-parser-gfm"
+# Ruby 3.4.0 removed some standard libraries that Jekyll uses
+# Depending on the jekyll/ruby configuration it should be already installed
+gem "webrick"
+gem "csv"
+gem "base64"
+gem "bigdecimal"