Make GMM documentation more visible, fix bug in M step of EM algorithm

[geoff-davis]

No description provided.

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[codecov-commenter]

Codecov Report

Merging #144 (37c9393) into main (cca7453) will increase coverage by 7.11%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #144      +/-   ##
==========================================
+ Coverage   82.77%   89.88%   +7.11%     
==========================================
  Files          51       51              
  Lines        4946     4944       -2     
  Branches      502      502              
==========================================
+ Hits         4094     4444     +350     
+ Misses        702      379     -323     
+ Partials      150      121      -29     

Impacted Files	Coverage Δ
ott/tools/gaussian_mixture/fit_gmm_pair.py	79.26% <100.00%> (+2.15%)	⬆️
ott/core/neuraldual.py	70.14% <0.00%> (+0.74%)	⬆️
ott/geometry/grid.py	91.15% <0.00%> (+0.88%)	⬆️
ott/tools/gaussian_mixture/fit_gmm.py	75.60% <0.00%> (+1.21%)	⬆️
ott/geometry/low_rank.py	97.67% <0.00%> (+1.55%)	⬆️
ott/core/quad_initializers.py	89.65% <0.00%> (+1.72%)	⬆️
ott/core/quad_problems.py	88.50% <0.00%> (+2.00%)	⬆️
ott/core/initializers.py	100.00% <0.00%> (+2.12%)	⬆️
ott/core/sinkhorn_lr.py	96.55% <0.00%> (+2.58%)	⬆️
... and 21 more

[marcocuturi]

Thanks Geoff! LGTM