v1.8.1 URL check fix

Wiki/Documentation updates

• Most common errors and how to fix them are documented here: https://github.com/jhudsl/OTTR_Template/wiki/Most-common-errors-and-pitfalls

Template/style changes:

• Add template description that has the links to different course formats: leanpub, coursera, bookdown.

Github action changes:

• Fix the URL checker since the one we were using no longer supports Rmds #514
• Other minor handling updates in regards to spelling checks

Docker image updates:

• None

What's Changed

• Try to fix merge conflict by @cansavvy in #474
• Cansavvy/merge conflict by @cansavvy in #475
• Add docker image as option by @cansavvy in #479
• Add a "no quizzes" handling ability as well as some merge conflict resolutions by @cansavvy in #480
• Switch handling of spell check errors by @cansavvy in #486
• One more spell check edit by @cansavvy in #489
• Wiki images by @carriewright11 in #491
• Save url check to a file like the other checks do by @cansavvy in #490
• Update sync.yml by @avahoffman in #494
• Change AnVIL Template Name by @avahoffman in #497
• Update update-enrollment.md by @KatherineCox in #505
• Delete style_coursera.css by @cansavvy in #508
• Add report-maker.yml here. by @cansavvy in #512
• Write our own url-checking script and get away from using url-checker-actions by @cansavvy in #515
• Add course formats bullet point template by @cansavvy in #516
• Update scripts so url check is fixed by @cansavvy in #518
• Add ability to ignore a url in the url checker by @cansavvy in #520

Full Changelog: 1.8...1.8.1