IIRR-34: Render puzzles's code with code-style

[arielj]

This PR adds code-style around code inside puzzles.

This makes it easier to review them since some cases were problematic before:

• html in puzzles was not escaped, so the actual HTML elements were rendered

• it was easy to miss basic typos like using 4 backticks instead of 1, or not adding a new line around the backticks

• it was easy to miss mismatched backticks for inline code

Now, code is rendered in the table:

[JuanVqz]

The rendered code looks good, I was expecting having colors :) maybe next iteration, thanks @arielj

[JuanVqz]

Just for the record, Since this is under our control, we can leave it as it is, but we are going to render HTML tags and test it with the following record:

Puzzle.create!(question: "test `<script>alert(1)</script>`", answer: :ruby, explanation: "loose <img src=x onerror=alert(1)>", state: :pending)

This is a safer way to do it:

Suggested change

	def markdown(text)
	RedcarpetCompat.new(text, :fenced_code).to_html.html_safe
	end
	def markdown(text)
	r = Redcarpet::Render::HTML.new(escape_html: true)
	Redcarpet::Markdown.new(r, fenced_code_blocks: true).render(text.to_s).html_safe
	end

[arielj]

updated

[arielj]

The rendered code looks good, I was expecting having colors :) maybe next iteration, thanks @arielj

I think we should leave it without colors since the language hints are not supported by Discord, Discord does not show colors.