Tiny documentation edits [ci skip]

actionpack/lib/action_dispatch/http/response.rb

@@ -201,7 +201,7 @@ module ActionDispatch # :nodoc:
     # it sets the charset to utf-8.
     #
     #   response.charset = 'utf-16' # => 'utf-16'
-    #   response.charset = nil # => 'utf-8'
+    #   response.charset = nil      # => 'utf-8'
     def charset=(charset)
       @charset = charset.nil? ? self.class.default_charset : charset
     end

activesupport/lib/active_support/core_ext/object/duplicable.rb

@@ -81,7 +81,7 @@ class BigDecimal
   # BigDecimals are duplicable:
   #
   # BigDecimal.new("1.2").duplicable? # => true
-  # BigDecimal.new("1.2").dup # => #<BigDecimal:7f9d698eee10,'0.12E1',18(18)>
+  # BigDecimal.new("1.2").dup         # => #<BigDecimal:...,'0.12E1',18(18)>
   def duplicable?
     true
   end

guides/source/getting_started.md

@@ -23,10 +23,12 @@ application from scratch. It does not assume that you have any prior experience
 with Rails. However, to get the most out of it, you need to have some
 prerequisites installed:
 
-* The [Ruby](https://www.ruby-lang.org/en/downloads) language version 2.2.2 or newer. 
-* Right version of [Development Kit](http://rubyinstaller.org/downloads/), if you are using Windows
-* The [RubyGems](https://rubygems.org) packaging system, which is installed with Ruby
-  versions 1.9 and later. To learn more about RubyGems, please read the [RubyGems Guides](http://guides.rubygems.org).
+* The [Ruby](https://www.ruby-lang.org/en/downloads) language version 2.2.2 or newer.
+* Right version of [Development Kit](http://rubyinstaller.org/downloads/), if you
+  are using Windows.
+* The [RubyGems](https://rubygems.org) packaging system, which is installed with
+  Ruby by default. To learn more about RubyGems, please read the
+  [RubyGems Guides](http://guides.rubygems.org).
 * A working installation of the [SQLite3 Database](https://www.sqlite.org).
 
 Rails is a web application framework running on the Ruby programming language.