fix key takeaway parsing
rewrite parsing to include proper bullets in markdown

- the parse_learning_objectives function is essentially the same as the
  parse_takeaways function (they operate identically) so I redesigned
  parse_keytakeaways so it can be used as a wrapper for
  parse_learning_objectives
- in some cases, the prescence of a table element in the original html
  can translate to a shitton of newline characters in the markdown file,
  so there is mitigation for that