Set up GitHub Pages compatibility with new Gemfile and scripts

- Updated Gemfile for GitHub Pages compatibility, including necessary gems.
- Added Gemfile.github-pages for specific GitHub Pages dependencies.
- Created scripts to switch between GitHub Pages and local development setups.
- Introduced GitHub Actions workflow for building and deploying the Jekyll site to GitHub Pages.

Gemfile.github-pages

@@ -0,0 +1,20 @@
+source 'https://rubygems.org'
+
+# GitHub Pages compatible gems
+gem 'github-pages', group: :jekyll_plugins
+gem 'jekyll-feed', '~> 0.12'
+gem 'jekyll-sitemap'
+
+# 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]