You might have all noticed that https://mathoverflow.net/help/formatting does not mention (La)TeX. I believe this is a very important topic and should not be hidden in "advanced"; actually, a link should already be here: https://mathoverflow.net/help
Notice that also https://mathoverflow.net/editing-help#latex is not very helpful for newcomers, who might not even know what LaTeX is. E.g. a bright undergraduate student might not know LaTeX, but still be a meaningful contributor to MO.
Yes, I know that on the question asking page it is better, but on the other hand it certainly is a problem if one wants to ask a question, but cannot find out how to typeset it in an acceptable way before actually starting to type the question up anyway.
Perhaps MO should indeed follow suit of
math.se, as explained in the answer by