fix: Gemfile & Gemfile.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-ACTIVESUPPORT-569598
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-1293239
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-6056551
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-6056552
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-6056553
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-6056554
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-6056555
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-7164639
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-8732769
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-8732779
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-2415031
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-3318400
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-5829860
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-2840634
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-2413994
- https://snyk.io/vuln/SNYK-RUBY-ADDRESSABLE-1316242
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-1726792
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-2620374
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-2630623
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-2630898
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-3052880
- https://snyk.io/vuln/SNYK-RUBY-TZINFO-2958048
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-5603112
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-9510795
- https://snyk.io/vuln/SNYK-RUBY-KRAMDOWN-585939
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-3318401
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-6228056
- https://snyk.io/vuln/SNYK-RUBY-ACTIVESUPPORT-3360028
- https://snyk.io/vuln/SNYK-RUBY-KRAMDOWN-1087436
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-3318398
- https://snyk.io/vuln/SNYK-RUBY-ACTIVESUPPORT-3237242
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-5603111
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-9510789
- https://snyk.io/vuln/SNYK-RUBY-COMMONMARKER-3318399
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-9789079
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-1055008
- https://snyk.io/vuln/SNYK-RUBY-NOKOGIRI-8453714

Author: snyk-bot

Gemfile

@@ -1,5 +1,5 @@
 source "https://rubygems.org"
 
-gem 'github-pages', '>= 201'
-gem 'html-proofer', '>= 3.13.0'
+gem 'github-pages', '>= 224'
+gem 'html-proofer', '>= 3.15.0'
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw]