Modernize language in INSTALL.md [ci skip]

Author: olleolleolle

INSTALL.md

@@ -1,21 +1,23 @@
 # Ruby OpenID Library Installation
 
-## Rubygems Installation
+## Install as a gem
 
-Rubygems is a tool for installing ruby libraries and their
-dependancies. If you have rubygems installed, simply:
+`ruby-openid` is distributed on [RubyGems](https://rubygems.org/).
+Install it:
 
     gem install ruby-openid
 
+This is probably what you need.
+
 ## Manual Installation
 
-Unpack the archive and run setup.rb to install:
+Unpack the archive and run `setup.rb` to install:
 
     ruby setup.rb
 
-setup.rb installs the library into your system ruby. If don't want to
+`setup.rb` installs the library into your system ruby. If don't want to
 add openid to you system ruby, you may instead add the `lib` directory of
-the extracted tarball to your RUBYLIB environment variable:
+the extracted tarball to your `RUBYLIB` environment variable:
 
     $ export RUBYLIB=${RUBYLIB}:/path/to/ruby-openid/lib
 
@@ -27,21 +29,13 @@ Make sure everything installed ok:
     irb$> require "openid"
     => true
 
-Or, if you installed via rubygems:
-
-    $> irb
-    irb$> require "rubygems"
-    => true
-    irb$> require_gem "ruby-openid"
-    => true
-
 ## Run the test suite
 
 Go into the test directory and execute the `runtests.rb` script.
 
 ## Next steps
 
-* Run `consumer.rb` in the examples directory.
-* Get started writing your own consumer using OpenID::Consumer
+* Run `consumer.rb` in the `examples/` directory.
+* Get started writing your own consumer using `OpenID::Consumer`
 * Write your own server with `OpenID::Server`
-* Use the `OpenIDLoginGenerator`! Read `example/README.md` for more info.
+* Use the `OpenIDLoginGenerator`! Read `examples/README.md` for more info.