docs: fix overview and add bark

[piksel]

Fix example URLs for services and add the new Bark service.

[codecov]

Codecov Report

Merging #255 (2827bab) into main (66c185c) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #255   +/-   ##
=======================================
  Coverage   77.85%   77.85%           
=======================================
  Files          96       96           
  Lines        2877     2877           
=======================================
  Hits         2240     2240           
  Misses        466      466           
  Partials      171      171           

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