Merge pull request #6360 from Homebrew/dependabot/bundler/docs/html-pipeline-2.12.0

build: bump html-pipeline from 2.11.1 to 2.12.0 in /docs

docs/Gemfile.lock

@@ -81,7 +81,7 @@ GEM
       octokit (~> 4.0)
       public_suffix (~> 3.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.11.1)
+    html-pipeline (2.12.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     html-proofer (3.11.1)