Use github-pages gem

This helps maintain a Jekyll build environment that matches the GH Pages build environment.

Tested locally with Jekyll 4.4.1 (version requirement remains commented out in Gemfile).

Docs:
https://docs.github.com/en/pages/setting-up-a-github-pages-site-with-jekyll/creating-a-github-pages-site-with-jekyll

"github-pages" version 232 in Gemfile per https://pages.github.com/versions.json

Author: anssiko

Gemfile

@@ -7,12 +7,12 @@ source "https://rubygems.org"
 #
 # This will help ensure the proper Jekyll version is running.
 # Happy Jekylling!
-# gem "jekyll", "~> 4.2.0"
+# gem "jekyll", "~> 4.4"
 # This is the default theme for new Jekyll sites. You may change this to anything you like.
 gem "minima", "~> 2.5"
 # If you want to use GitHub Pages, remove the "gem "jekyll"" above and
 # uncomment the line below. To upgrade, run `bundle update github-pages`.
-# gem "github-pages", group: :jekyll_plugins
+gem "github-pages", "~> 232", group: :jekyll_plugins
 # If you have any plugins, put them here!
 group :jekyll_plugins do
   gem "jekyll-feed", "~> 0.12"

README.md

@@ -5,7 +5,7 @@ W3C Web Machine Learning Working Group and Community Group website.
 ## Environment Setup
 
 ```
-gem install bundler jekyll
+gem install bundler jekyll github-pages
 ```
 
 ## Run
@@ -16,6 +16,14 @@ bundle exec jekyll serve
 Server address: http://127.0.0.1:4000/
 ```
 
+## Update Jekyll and Dependencies
+
+The [GitHub Pages gem](https://github.com/github/pages-gem) (`github-pages`) helps maintain a Jekyll build environment that most closely matches the GitHub Pages build environment. To update Jekyll and its dependencies:
+
+```
+bundle update github-pages
+```
+
 ## Contributing
 
 We welcome contributions! Please see the [contributing guidelines](CONTRIBUTING.md).