Update repo settings to require link check [requires maintainer]

[dlebauer]

After merging #135

• Actions → confirm workflow Link Check appears.
• Actions → Link Check → Run workflow → Branch: main → Run.
• Settings → Rules → Rulesets → edit/create ruleset:
  • Target branches: include main
  • Check Require status checks to pass
  • Add required check: Check links with lychee
  • Save

[dlebauer]

update: did not have to wait for 135 to be merged.