DOC: update styler user guide for ref to hiding cols and index and link to to_LaTeX
should be backported to 1.3.0 as it references the features add there.

Thanks @attack68 web and docs is failing on rate limit exceeded. As this PR changes docs will need to re-run later to make sure this is green. @simonjayhawkins this is green now thanks @attack68  @meeseeksdev backport 1.3.x Something went wrong ... Please have  a look at my logs.