anchor.diff:  
    $ bundle
   
  -To upgrade the gem, set the new version in the Gemfile and run `bundle` again.
  +To upgrade the gem, specify the new version in the Gemfile and run `bundle` again.
   Using `bundle update` is not recommended as it will also update other gems, which may not be the desired result.
   
   === (c) Linux package managers
  
positive.code: 
  === Other installation options
  
  * {install-doc-uri}[Installing the Asciidoctor toolchain]
  * {install-osx-doc-uri}[Installing Asciidoctor on Mac OS X]
  
  == Usage
  
  If the Asciidoctor gem installed successfully, the `asciidoctor` command line interface (CLI) will be available on your PATH.
  To verify it's installed correctly, run the following in your terminal:
  
   $ asciidoctor --version
  
  You should see information about the Asciidoctor version and your Ruby environment printed in the terminal.
  
    Asciidoctor 1.5.0 [http://asciidoctor.org]
    Runtime Environment (ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-linux])
  
  Asciidoctor also provides an API.
  The API is intended for integration with other Ruby software, such as Rails, Sinatra and GitHub, and other languages, such as Java (via {asciidoctorj-uri}[AsciidoctorJ]) and JavaScript (via {asciidoctorjs-uri}[Asciidoctor.js]).
  
  === Command line interface (CLI)
  
  The `asciidoctor` command allows you to invoke Asciidoctor from the command line (i.e., a terminal).
  
  The following command converts README.adoc to HTML and saves the result to the file README.html in the same directory.
  The name of the generated HTML file is derived from the source file by changing its file extension to `.html`.
  
   $ asciidoctor README.adoc
  
negative.code: Asciidoctor can be installed using (a) the `gem install` command, (b) Bundler or (c) package managers for popular Linux distributions.
  
  TIP: The benefit of using a Linux package manager to install the gem is that it handles installing Ruby and the RubyGems library if those packages are not already installed on your machine.
  The drawback is that the package may not be available immediately after the release of the gem.
  If you need the latest version, you can always fallback to using the `gem` command.
  
  === (a) gem install
  