README.md in neco-0.1.0 vs README.md in neco-0.2.0

@@ -1,11 +1,12 @@
+[![Build Status](https://travis-ci.com/okuramasafumi/neco.svg?branch=master)](https://travis-ci.com/okuramasafumi/neco)
+[![Maintainability](https://api.codeclimate.com/v1/badges/d011a37ef8ebf1ea2afd/maintainability)](https://codeclimate.com/github/okuramasafumi/neco/maintainability)
+
 # Neco
 
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/neco`. To experiment with that code, run `bin/console` for an interactive prompt.
+Neco is a NEo COmmand pattern library for Ruby.
 
-TODO: Delete this and the text above, and describe your gem
-
 ## Installation
 
 Add this line to your application's Gemfile:
 
 ```ruby
@@ -20,24 +21,92 @@
 
     $ gem install neco
 
 ## Usage
 
-TODO: Write usage instructions here
+Include `Neco::Command` module and define your command with DSLs like below:
 
+```ruby
+class Foo
+  include Neco::Command
+
+  validates do |name:|
+    name == 'Tama'
+  end
+
+  main do |name:|
+    puts "Hello, #{name}!"
+  end
+end
+
+Foo.call(name: 'Tama') # => 'Hello, Tama!'
+```
+
+Here, `validates` block defines validations and `main` block defines main logic for the command (simple, right?)
+
+You can also compose multiple commands into one command using `Neco::Composition` module. Neco automatically triggers rollbacks when one of the commands raises an exception.
+
+```ruby
+class Command1
+  include Neco::Command
+
+  main do
+    set :cat_name, 'Tama'
+  end
+
+  rollback do
+    puts 'Rolling back Command1!'
+  end
+end
+
+class Command2
+  include Neco::Command
+
+  main do |cat_name:|
+    puts "Hello, #{cat_name}!"
+  end
+
+  rollback do
+    puts 'Rolling back Command2!'
+  end
+end
+
+class Command3
+  include Neco::Command
+
+  # Unused block argument
+  main do |cat_name:|
+    raise 'OMG!!!'
+  end
+end
+
+class Bar
+  include Neco::Composition
+
+  composes Command1, Command2, Command3
+end
+
+Bar.call
+# => 'Hello, Tama!'
+# => 'Rolling back Command2!'
+# => 'Rolling back Command1!'
+```
+
+See `examples` directory for details.
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
 
 ## Contributing
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/neco. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.
+Bug reports and pull requests are welcome on GitHub at https://github.com/okuramasafumi/neco. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.
 
 ## License
 
 The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
 
 ## Code of Conduct
 
-Everyone interacting in the Neco project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/[USERNAME]/neco/blob/master/CODE_OF_CONDUCT.md).
+Everyone interacting in the Neco project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/okuramasafumi/neco/blob/master/CODE_OF_CONDUCT.md).