docs: more workflow improvements.

- Add a special step to handle formulae.brew.sh API samples generation.
- Ignore the root URL: it always works and often is a false-positive
  failure.

While we're here:
- Autofix some RuboCop offenses in the Rakefile.

.github/workflows/docs.yml

@@ -63,6 +63,11 @@ jobs:
       - name: Check code blocks conform to our Ruby style guide
         run: brew style docs
 
+      - name: Generate formulae.brew.sh API samples
+        if: github.repository == 'Homebrew/formulae.brew.sh'
+        working-directory: docs
+        run: ../script/generate-api-samples.rb
+
       - name: Build the site and check for broken links
         working-directory: docs
         run: bundle exec rake test

docs/Rakefile

@@ -26,17 +26,18 @@ task test: :build do
     check_img_http:      true,
     enforce_https:       true,
     ignore_files:        [
-      %r{Kickstarter-Supporters},
+      /Kickstarter-Supporters/,
     ],
     ignore_urls:         [
+      "/",
       %r{https://formulae.brew.sh"},
       %r{https://github.com/},
-      'https://legacy.python.org/dev/peps/pep-0453/#recommendations-for-downstream-distributors',
+      "https://legacy.python.org/dev/peps/pep-0453/#recommendations-for-downstream-distributors",
     ],
     cache:               {
       timeframe: {
-        external: "1h"
-      }
-    }
+        external: "1h",
+      },
+    },
   ).run
 end