```ruby
include Nanoc::Helpers::LinkTo

module LinkHelpers

  #
  # get link for the category
  #
  def link_category name
    "<a href='/categories/#{name}'>#{name}</a>"
  end

  #
  # get links for the categories
  #
  def link_categories cs
    cs.map { |c| "<a href='/categories/#{c}'>#{c}</a>" }
  end

end

include LinkHelpers
```

Add link helper for linking articles
user
```ruby
include Nanoc::Helpers::LinkTo

module LinkHelpers

  #
  # get link for the category
  #
  def link_category name
    "<a href='/categories/#{name}'>#{name}</a>"
  end

  #
  # get links for the categories
  #
  def link_categories cs
    cs.map { |c| "<a href='/categories/#{c}'>#{c}</a>" }
  end

  #
  # link an article
  #
  def link_article name
    link_to name, "/articles/#{name.downcase.gsub(" ", "_")}"
  end

end

include LinkHelpers
```
assistant