fix: fallback to getting image file extension from url

fix: update readme to reflect change of css name

feat: copy the latest docu-notion-styles.css to output

Then it will be available to point to each site's docusaurus.config.js

Merge branch 'main' into release

Merge branch 'issue-68/latex-rendering-problem' into main

(Hatton corrected some linting problems during merge)

feat: Some checking and troubleshooting help for people just getting …

…started

Merge main into release

fix: use original block values upon retry

fix: embedded link regexes were too greedy

Merge pull request #81 from sillsdev/moreTimeoutResilience

fix: Increase timeout resilience (#81)