Update dunstctl manpage

[zappolowski]

This fixes #1280 and also the comment mentioned in #1242.

While at it, I also did a small reformatting of the page.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.52%. Comparing base (e5f188c) to head (1305961).
⚠️ Report is 316 commits behind head on master.
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1298   +/-   ##
=======================================
  Coverage   65.52%   65.52%           
=======================================
  Files          48       48           
  Lines        7997     7997           
=======================================
  Hits         5240     5240           
  Misses       2757     2757           

Flag	Coverage Δ
unittests	65.52% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ 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.

[bynect]

Could you also add history-clear?

[bynect]

All clear 👍🏻