If you put things in triple backticks ```, it’s formatted as a code block

Like this

I believe you can specify a language for syntax highlighting at the start of the code block.

SELECT * 
FROM passwords
WHERE storage_method = 'plaintext' 
-- TODO rename storage method to something less obvious so the IT-Sec guys get off my case

<p class="bold">Stop storing password in plain text, dammit</div>
<!-- TODO clean up the tags so the linter stops complaining -->

if (true) this.code.makeCringe(this.reader);
else 
    { 
throw new NullPointerException("Unreachable code"); }
// Why, yes, I do love creating terrible code

I don’t know what or how it guesses the language otherwise.

if (highlighting == "Python"): 
  System.out.println("Wait, that's not a Python command");
  std::cout << "Also not Python"
  print("This one is")

CASE highlighting 
  WHEN 'SQL' THEN 'I dont know any dialect-specific ways to check which one this is'
  WHEN 'sql' THEN 'Apparently its case-sensitive' 
  ELSE 'No clue' 
END 

(concatenate 'string "I can't be arsed to try everything I know" "So this will have to do")