Removed sentence in vignette about vectorized path argument for lint_dir()

[marberts]

Closes #2923.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.28%. Comparing base (84d3f8c) to head (90b2381).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2924   +/-   ##
=======================================
  Coverage   99.28%   99.28%           
=======================================
  Files         129      129           
  Lines        7266     7266           
=======================================
  Hits         7214     7214           
  Misses         52       52           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[MichaelChirico]

Thanks!