```ruby
# -*- encoding: utf-8 -*-
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'guideline/version'

Gem::Specification.new do |gem|
  gem.name          = "guideline"
  gem.version       = Guideline::VERSION
  gem.authors       = ["Ryo NAKAMURA"]
  gem.email         = ["ryo-nakamura@cookpad.com"]
  gem.description   = %q{TODO: Write a gem description}
  gem.summary       = %q{TODO: Write a gem summary}
  gem.homepage      = ""

  gem.files         = `git ls-files`.split($/)
  gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
  gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
  gem.require_paths = ["lib"]
end
```

Write the detail of gemspec
user
```ruby
# -*- encoding: utf-8 -*-
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'guideline/version'

Gem::Specification.new do |gem|
  gem.name          = "guideline"
  gem.version       = Guideline::VERSION
  gem.authors       = ["Ryo NAKAMURA"]
  gem.email         = ["r7kamura@gmail.com"]
  gem.description   = "Guideline.gem checks if your code observes your coding guidelines"
  gem.summary       = "The guideline of your code"
  gem.homepage      = "https://github.com/r7kamura/guideline"

  gem.files         = `git ls-files`.split($/)
  gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
  gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
  gem.require_paths = ["lib"]
end
```
assistant