Clean some formatting on create rails app page

this reduces the use of single-option option tags, which look all weird

Author: tjgrathwell

sites/installfest/create_and_deploy_a_rails_app.step

@@ -33,7 +33,7 @@ is the same as `rails server`.
 
   message <<-MARKDOWN
 The first command should produce no output.
-If "rails server" starts up with no errors, you're golden! It'll look something like this:
+If `rails server` starts up with no errors, you're golden! It'll look something like this:
   MARKDOWN
 
   result <<-TEXT
@@ -68,8 +68,7 @@ message <<-MARKDOWN
   end
 
 step "Generate a database model" do
-
-  option "if your prompt doesn't already show that you are (still) in the test_app folder" do
+  tip "If your prompt doesn't already show that you are (still) in the test_app folder" do
     console "cd test_app"
   end
 
@@ -88,8 +87,7 @@ rails server
 end
 
 step "Use git" do
-
-  option "if your prompt doesn't already show that you are (still) in the test_app folder" do
+  tip "If your prompt doesn't already show that you are (still) in the test_app folder" do
     console "cd test_app"
   end
 
@@ -151,19 +149,23 @@ Git remote heroku added
 Find your test_app folder and open it in a text-editor.
 Inside, find a file named Gemfile.
 Edit your Gemfile and change the line:
+MARKDOWN
+  source_code :ruby, <<-RUBY
+gem 'sqlite3'
+  RUBY
 
-    gem 'sqlite3'
-
+  message <<-MARKDOWN
 To this:
+  MARKDOWN
 
-    group :development, :test do
-      gem 'sqlite3'
-    end
-    group :production do
-      gem 'pg'
-    end
-
-    MARKDOWN
+  source_code :ruby, <<-RUBY
+group :development, :test do
+  gem 'sqlite3'
+end
+group :production do
+  gem 'pg'
+end
+  RUBY
 
     console <<-BASH
 bundle install --without production