hash_pivot.gemspec in hash_pivot-0.3.0 vs hash_pivot.gemspec in hash_pivot-0.3.1

@@ -15,9 +15,10 @@
   spec.required_ruby_version = Gem::Requirement.new('>= 2.5.0')
 
   spec.metadata['homepage_uri'] = spec.homepage
   spec.metadata['source_code_uri'] = spec.homepage
   spec.metadata['changelog_uri'] = "#{spec.homepage}/blob/main/CHANGELOG.md"
+  spec.metadata['documentation_uri'] = 'https://rubydoc.info/gems/hash_pivot'
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
   spec.files = Dir.chdir(__dir__) do
     `git ls-files -z`.split("\x0").reject do |f|