Add ability to markup validator description

[exAspArk]

Hi!
I'm using config.markup = Apipie::Markup::Markdown.new and I have my custom validator:

class Apipie::Validator::StringQueryValidator < Apipie::Validator::BaseValidator
  def initialize(param_description, argument, options)
    super(param_description)
  end

  def validate(value)
    !!(value =~ /^[^&*\/\^]+$/)
  end

  def self.build(param_description, argument, options, block)
    if options[:validator] == :query
      self.new(param_description, argument, options)
    end
  end

  def description
    'Must have any characters except: `/` `&` `^` `*`'
  end
end

I'd like to make this description highlighted 😺

[iNecas]

I wonder if we shouldn't have the Apipie.markup_to_html(params[:validator]).html_safe here. The reasons:

1. through the JSON api that apipie provides, I would expect the non-html version
2. when adding new validator, one would always need to not forget to wrap that into the Apipie.markup_to_html('...')

[exAspArk]

@iNecas I agree. What about using markup_to_html in partials?

[iNecas]

+1 on that

[exAspArk]

@iNecas updated :)

[iNecas]

Looks good, Thanks!

[iNecas]

I'm happy to announce that the new version 0.3.0 was released, including this change. Thanks for making that happen https://github.com/Apipie/apipie-rails/blob/master/CHANGELOG.md#v030