Add estimagic logo to documentation page

[mpetrosian]

No description provided.

[codecov]

Codecov Report

Merging #467 (c661dc7) into main (fcd95f1) will increase coverage by 0.47%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #467      +/-   ##
==========================================
+ Coverage   92.50%   92.98%   +0.47%     
==========================================
  Files         194      193       -1     
  Lines       14711    14613      -98     
==========================================
- Hits        13609    13588      -21     
+ Misses       1102     1025      -77     

Files Changed	Coverage Δ
src/estimagic/parameters/parameter_groups.py	100.00% <ø> (ø)
src/estimagic/optimization/tranquilo.py	88.88% <100.00%> (ø)

... and 2 files with indirect coverage changes

[timmens]

Okay, I'm just realizing that the img tag needs to be closed, since, otherwise the logo div spans much further than it should. On the attached image you see that the text below is also centered, this is because the centering in the logo div also applies to that section because the img tag is not closed.

[timmens]

Looks great, thank you!

[timmens]

I still don't understand why the mock import does not work for tranquilo, but at least the autodoc works now. I've also left the tranquilo_scalar change as it is, though I think it is not necessary to fix the bug.

[janosg]

I changed the name inside mark_minimizer back so we don't get a breaking change.