Ignore trailing blank lines after single-line title-page commands.

[fingolfin]

Trim generated title-page content to avoid stray newlines.
This prevents newline-bearing filenames and empty authors.

Co-authored-by: Codex codex@openai.com

[codecov]

Codecov Report

❌ Patch coverage is 97.14286% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.05%. Comparing base (d89ad60) to head (1145eb7).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
gap/AutoDocMainFunction.gi	95.23%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #333      +/-   ##
==========================================
+ Coverage   90.98%   91.05%   +0.06%     
==========================================
  Files          13       13              
  Lines        2529     2559      +30     
==========================================
+ Hits         2301     2330      +29     
- Misses        228      229       +1     

Files with missing lines	Coverage Δ
gap/Parser.gi	95.47% <100.00%> (+0.07%)	⬆️
gap/AutoDocMainFunction.gi	87.13% <95.23%> (+0.35%)	⬆️

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[fingolfin]

@mohamed-barakat with that the worksheet in your private repo builds again (well, with the bib file fix (needed by GAPDoc) and the removal of that @URL command (which we dropped support for over 10 years ago; but we may soon have Markdown style links as a better replacement). Afterwards, there are still some broken Refs: apparently if a chapter or (sub)section title contains characters like :, then those are stripped from auto-generated labels. I don't know yet if that's a recent regression or a change we made long ago (depending on that I can revert it, or not...). That said, I am not super happy with our current auto-label system, but that's another matter.