Remove a bunch of unnecessary blank lines

Use `trim_mode: -` from standard `erb` library since RDoc's doesn't seem
to support it.

And add some other small changes to the template to avoid generating
blank lines.

Rakefile

@@ -136,12 +136,10 @@ file 'command-reference.md' =>
 
   filename = "command-reference.erb"
 
-  erbio = RDoc::ERBIO.new File.read(filename), nil, nil
-  erbio.filename = filename
+  erbio = ERB.new File.read(filename), trim_mode: '-'
+  content = erbio.result binding
 
-  open 'command-reference.md', 'w' do |io|
-    erbio.result binding
-  end
+  File.write 'command-reference.md', content
 end
 
 desc "serve documentation on http://localhost:4000"

command-reference.erb

@@ -10,31 +10,28 @@ next: /rubygems-org-api
 
 This reference was automatically generated from RubyGems version <%= rubygems_version %>.
 
-<% commands.each do |name, command| %>* [gem <%= name %>](#gem-<%= name %>)
-<% end %>
+<%- commands.each do |name, command| -%><%= "* [gem #{name}](#gem-#{name})\n" %><%- end -%>
+<%- commands.each do |name, command| -%>
 
-<% commands.each do |name, command| %>
 ## gem <%= name %>
 
 <%= htmlify(command.summary) %>
 
 ### Usage
 
     <%= command.usage %> [options]
+<%= options_list(command).rstrip + "\n" -%>
+<%- if command.arguments != "" -%>
 
-<%= options_list(command) %>
-
-<% if command.arguments != "" %>
 ### Arguments
 
-<% arguments = command.arguments.split("\n") %>
-<% arguments.each do |argument| %><%= argument_list_item(argument) %>
-<% end %>
-<% end %>
+<%- command.arguments.split("\n").each do |argument| -%><%= argument_list_item(argument) %>
+<%- end -%>
+<%- end -%>
+<%- if command.description && command.description != "" -%>
 
-<% if command.description && command.description != "" %>
 ### Description
 
 <%= htmlify(command.description).gsub(/^  /, "    ") %>
-<% end %>
-<% end %>
+<%- end -%>
+<%- end -%>