fix: Fixed landing page and title underlines

[fg-mindee]

This PR introduces the following modifications:

• fixed the indentation of the paper list on the landing page
• fixed the underline of a section's subtitle

Any feedback is welcome!
cc @felixdittrich92 (since this was completely independent from the rest)

[codecov]

Codecov Report

Merging #860 (26dd5b3) into main (fc8efc9) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #860      +/-   ##
==========================================
- Coverage   94.84%   94.82%   -0.02%     
==========================================
  Files         133      133              
  Lines        5200     5200              
==========================================
- Hits         4932     4931       -1     
- Misses        268      269       +1     

Flag	Coverage Δ
unittests	94.82% <ø> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
doctr/transforms/functional/base.py	95.65% <0.00%> (-1.45%)	⬇️

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[charlesmindee]

Thanks FG !