docs: use sphinxcontrib-bibtex to build bibliography

[tsutterley]

refactor: moved check points function to compute
docs: unify all references to a single bibliography

[codecov]

Codecov Report

Attention: Patch coverage is 64.91228% with 20 lines in your changes missing coverage. Please review.

Project coverage is 70.14%. Comparing base (e1eccc0) to head (be14b99).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
pyTMD/compute.py	61.70%	11 Missing and 7 partials ⚠️
pyTMD/check_points.py	60.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #372      +/-   ##
==========================================
- Coverage   71.07%   70.14%   -0.94%     
==========================================
  Files          43       43              
  Lines       10522    10666     +144     
  Branches     1138     1152      +14     
==========================================
+ Hits         7479     7482       +3     
- Misses       2580     2721     +141     
  Partials      463      463              

Flag	Coverage Δ
unittests	70.14% <64.91%> (-0.94%)	⬇️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.