Bump html-pipeline from 2.5.0 to 2.11.0

Bumps [html-pipeline](https://github.com/jch/html-pipeline) from 2.5.0 to 2.11.0.
- [Release notes](https://github.com/jch/html-pipeline/releases)
- [Changelog](https://github.com/jch/html-pipeline/blob/master/CHANGELOG.md)
- [Commits](gjtorikian/html-pipeline@v2.5.0...v2.11.0)

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

Gemfile.lock

@@ -92,7 +92,7 @@ GEM
       concurrent-ruby (~> 1.0)
     hashdiff (0.3.7)
     hashie (3.6.0)
-    html-pipeline (2.5.0)
+    html-pipeline (2.11.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.6.0)