fix: Hashnode table width

[scissorsneedfoodtoo]

Checklist:

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)

Currently Hashnode tables don't have a fixed width, so they overflow from the main content container on the page making them impossible to read.

Here is a Hashnode sourced post with a table showing this issue: https://www.freecodecamp.org/news/javascript-keycode-list-keypress-event-key-codes/

This fix combines some existing styling for tables and sets a max-width for divs with the hn-table class, which should fix the issue.