Actualize gemspec

Remake homepage, add a lot of metadata,
including `rubygems_mfa_required` to resolve RuboCop offense.

Author: AlexWayfer

grape-swagger-representable.gemspec

@@ -9,14 +9,25 @@ Gem::Specification.new do |s|
   s.email         = ['[email protected]']
 
   s.summary       = 'Grape swagger adapter to support representable object parsing'
-  s.homepage      = 'https://github.com/ruby-grape/grape-swagger-representable'
   s.license       = 'MIT'
 
   s.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
   s.bindir        = 'exe'
   s.executables   = s.files.grep(%r{^exe/}) { |f| File.basename(f) }
   s.require_paths = ['lib']
 
+  github_uri = "https://github.com/ruby-grape/#{s.name}"
+
+  s.homepage = github_uri
+
+  s.metadata = {
+    'rubygems_mfa_required' => 'true',
+    'bug_tracker_uri' => "#{github_uri}/issues",
+    'documentation_uri' => "http://www.rubydoc.info/gems/#{s.name}/#{s.version}",
+    'homepage_uri' => s.homepage,
+    'source_code_uri' => github_uri
+  }
+
   s.required_ruby_version = '>= 2.7', '< 4'
 
   s.add_runtime_dependency 'grape-swagger', '~> 2.0'