IIRR-34: Fix newlines around codeblocks for Redcarpet renderer

[arielj]

My previous PR #93 adding code style introduced a bug: redcarpets needs the first three-backticks of a codeblock to have 2 newlines before it to render it properly.

This is not required for the closing three-backticks and also not required by discord either.

Because of this, some of our puzzles that don't have 2 newlines before the start of a codeblock were rendered incorrectly, parsing the code that should have been part of a code block as HTML instead.

This PR fixes that by fixing the missing newline during render if needed.

I didn't add a fix in the data stored in the database because it's not really a requirement for Discord, it's just a weird thing with Redcarpet so it's fixed on the fly as needed when rendered.

I also added a bit of space after the code block because it looked too close to the next line because of how redcarpet renders pre and p tags

[JuanVqz]

The requex you added is eathing the h of with, this worked for me:

Suggested change

	text = text.gsub(/[^\n]\n```(.*)\n```/m, "\n\n```\\1\n```")
	text = text.gsub(/([^\n])\n```(.*?)\n```/m, "\\1\n\n```\\2\n```")