Refactor prompt to explicitly mention equation code formatting

[markovial]

If we want equations to be generated in LaTeX and if we want to consider displaying them properly rendered on site after they have been generated.

So it might be worth explicitly mentioning to the LLM that they have to be properly formatted in the way we want with proper start, end, whitespace etc... tags as required by our rendering engine.

[FraserLee]

link: #77