Bump nokogiri from 1.11.7 to 1.13.0 in /docs

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.11.7 to 1.13.0.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](https://github.com/sparklemotion/nokogiri/compare/v1.11.7...v1.13.0

)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/Gemfile.lock

@@ -227,7 +227,7 @@ GEM
       jekyll-seo-tag (~> 2.1)
     minitest (5.14.4)
     multipart-post (2.1.1)
-    nokogiri (1.11.7-x86_64-linux)
+    nokogiri (1.13.0-x86_64-linux)
       racc (~> 1.4)
     nokogumbo (2.0.5)
       nokogiri (~> 1.8, >= 1.8.4)
@@ -238,7 +238,7 @@ GEM
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.6)
-    racc (1.5.2)
+    racc (1.6.0)
     rainbow (3.0.0)
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)