Small fixes and doc updates

[lkdvos]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.42%. Comparing base (52f1a78) to head (306aae0).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #94      +/-   ##
==========================================
- Coverage   84.62%   82.42%   -2.21%     
==========================================
  Files          31       31              
  Lines        3318     3271      -47     
==========================================
- Hits         2808     2696     -112     
- Misses        510      575      +65     

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[Jutho]

From Lapack's dhseqr.f docstring:

*     INFO  (output) INTEGER
*             =  0:  successful exit
*           .LT. 0:  if INFO = -i, the i-th argument had an illegal
*                    value
*           .GT. 0:  if INFO = i, [DHSEQR](https://www.netlib.org/lapack/explore-3.1.1-html/dhseqr.f.html#DHSEQR.1) failed to compute all of
*                the eigenvalues.  Elements 1:ilo-1 and i+1:n of WR
*                and WI contain those eigenvalues which have been
*                successfully computed.  (Failures are rare.)

So we hit a rare failure 😄. I'll merge.