Don't use htmlproofer 4.0.0 or newer

tannewt · web-flow · commit 8273b0f87155 · 2022-08-05T10:29:47.000-07:00
It removes internal_domains.
diff --git a/Gemfile b/Gemfile
@@ -11,4 +11,4 @@ end
 gem "github-pages", versions['github-pages']
 gem "redcarpet"
 
-gem "html-proofer", '>=3.3.1'
+gem "html-proofer", '>=3.3.1', '<4.0.0'
