chore(deps): update ruby packages (#246)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

docs/Gemfile

@@ -1,13 +1,13 @@
 source "https://rubygems.org"
 
 group :jekyll_plugins do
-  gem "github-pages", "~> 209"
+  gem "github-pages", "~> 232"
 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", "~> 1.2"
+  gem "tzinfo", "~> 2.0"
   gem "tzinfo-data"
 end