Node#to_html with plugins does not work.

[wakairo]

I tested the following code and it seems that the keyword argument "plugins" of Node#to_html does not make an effect on the version 1.1.2.

require 'commonmarker'

puts Commonmarker::VERSION # => 1.1.2

code = <<~CODE
  ```ruby
  puts "hello"
  ```
CODE
plugins = { syntax_highlighter: { theme: "InspiredGitHub" } }

p Commonmarker.to_html(code, plugins: plugins)
# => "<pre lang=\"ruby\" style=\"background-color:#ffffff;\"><code><span style=\"color:#62a35c;\">puts </span><span style=\"color:#183691;\">&quot;hello&quot;\n</span></code></pre>\n"

doc = Commonmarker.parse(code)
p doc.to_html(plugins: plugins)
# => "<pre lang=\"ruby\"><code>puts &quot;hello&quot;\n</code></pre>\n"
p doc.to_html
# => "<pre lang=\"ruby\"><code>puts &quot;hello&quot;\n</code></pre>\n"

[gjtorikian]

Thank you for the report! I haven't had time to look into this but I will soon.