various improvements to gemspec

1. add more metadata
2. simpler require for version file
3. \n-proff way of gathering files for inclusion in gem

Author: slonopotamus

pygments.rb.gemspec

@@ -1,27 +1,32 @@
 # frozen_string_literal: true
 
-require File.expand_path('lib/pygments/version', __dir__)
+require_relative 'lib/pygments/version'
 
 Gem::Specification.new do |s|
   s.name = 'pygments.rb'
   s.version = Pygments::VERSION
 
   s.summary = 'pygments wrapper for ruby'
   s.description = 'pygments.rb is a Ruby wrapper for Pygments syntax highlighter'
-
+  s.license = 'MIT'
   s.homepage = 'https://github.com./pygments/pygments.rb'
-  s.required_ruby_version = '>= 2.3.0'
 
   s.authors = ['Aman Gupta', 'Ted Nyman', 'Marat Radchenko']
   s.email = ['[email protected]']
-  s.license = 'MIT'
+
+  s.metadata = {
+    'homepage_uri' => s.homepage,
+    'bug_tracker_uri' => s.homepage + '/issues',
+    'changelog_uri' => s.homepage + '/blob/master/CHANGELOG.adoc',
+    'documentation_uri' => 'https://www.rubydoc.info/gems/' + s.name,
+    'source_code_uri' => s.homepage
+  }
+
+  s.required_ruby_version = '>= 2.3.0'
 
   s.add_development_dependency 'rake', '~> 13.0.0'
   s.add_development_dependency 'rubocop', '~> 0.81.0'
   s.add_development_dependency 'test-unit', '~> 3.4.0'
 
-  # s.extensions = ['ext/extconf.rb']
-  s.require_paths = ['lib']
-
-  s.files = `git ls-files`.split("\n").reject { |f| File.symlink?(f) } + ['lexers']
+  s.files = `git ls-files -z`.split("\0").reject { |f| File.symlink?(f) }
 end