Add "Read more" link to cleantalk page

[alexander-b-clean]

https://app.doboard.com/1/task/33372

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 14.46%. Comparing base (c1de423) to head (e41f4d8).
⚠️ Report is 32 commits behind head on dev.

Files with missing lines	Patch %	Lines
inc/cleantalk-settings.php	0.00%	1 Missing ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (70.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff              @@
##                dev     #782      +/-   ##
============================================
+ Coverage     14.02%   14.46%   +0.43%     
- Complexity     5480     5543      +63     
============================================
  Files           262      263       +1     
  Lines         27149    27231      +82     
============================================
+ Hits           3809     3939     +130     
+ Misses        23340    23292      -48     

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[Copilot]

Pull request overview

Updates a CleanTalk settings field description to include a help/documentation link.

Changes:

• Appends a “Read more” external link to the data__email_check_exist_post setting description.

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