feat: enable configuration options for PDF title and file name

[tang-mm]

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Description

The current latex template defined the $PROJECT value as the PDF document title, so it was not possible to pass a new title from the configuration file.

This PR changed the default title to \thetitle in Latex and leverages the Sphinx latex_documents configuration variable to overwrite default values:

• if thelatex_documents variable is not defined, the default title and output filename are the same as before
• if the variable is defined (as provided in example/conf.py), new values are used

Usage and documentation link are added to the example configuration file.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 24.48%. Comparing base (5a4416e) to head (b0f7714).
Report is 43 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##              main      #67       +/-   ##
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- Coverage   100.00%   24.48%   -75.52%     
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  Files            1        3        +2     
  Lines           10       98       +88     
  Branches         2       16       +14     
============================================
+ Hits            10       24       +14     
- Misses           0       74       +74     

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