Documentation link added

[jdocksey]

Description

I added a missing documentation link to htmx.org/reference/, and fixed a typo.

Corresponding issue: n/a

Checklist

• I have read the contribution guidelines
• I have targeted this PR against the correct branch (master for website changes, dev for
  source changes)
• This is either a bugfix, a documentation update, or a new feature that has been explicitly
  approved via an issue
• I ran the test suite locally (npm run test) and verified that it succeeded