feat: implement auto excludes option

[machow]

This PR implements the exclude option for documenting items. This option is currently documented, but marked unimplemented.

[codecov-commenter]

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

Codecov Report

Attention: Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Project coverage is 88.72%. Comparing base (7d07fbb) to head (90d83d3).

Files with missing lines	Patch %	Lines
quartodoc/builder/blueprint.py	75.00%	1 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #372      +/-   ##
==========================================
+ Coverage   88.65%   88.72%   +0.06%     
==========================================
  Files          37       37              
  Lines        2953     2961       +8     
==========================================
+ Hits         2618     2627       +9     
+ Misses        335      334       -1     

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