docs: several fixes in docstrings

[d0choa]

Trivial fixes. I thought we were picking up this kind of errors somewhere in the precommits but it doesn't seem to be the case.

[codecov-commenter]

Codecov Report

Merging #170 (84e8de5) into main (cc1f636) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #170   +/-   ##
=======================================
  Coverage   90.74%   90.74%           
=======================================
  Files          67       67           
  Lines        1459     1459           
=======================================
  Hits         1324     1324           
  Misses        135      135           

Files	Coverage Δ
src/otg/config.py	100.00% <100.00%> (ø)
src/otg/datasource/finngen/study_index.py	100.00% <ø> (ø)
src/otg/datasource/intervals/andersson.py	100.00% <ø> (ø)
src/otg/datasource/intervals/javierre.py	100.00% <100.00%> (ø)
src/otg/datasource/intervals/jung.py	100.00% <100.00%> (ø)
src/otg/datasource/intervals/thurman.py	100.00% <100.00%> (ø)
src/otg/v2g.py	66.66% <100.00%> (ø)

[DSuveges]

OK, I'm quite sure it is not Thurnman but Thurman. This name is wrongly spelled across the repo. Could you fix them as well? It's very marginal detail, however fits well into the scope of the PR.

[d0choa]

Thurman instead of Thurnman changes implemented. Tests passing

[DSuveges]

Looks good. Thanks