Add examples section to locate module

[gegen07]

Closes #190.

[codecov]

Codecov Report

Merging #198 (db04d21) into main (06ae670) will increase coverage by 0.2%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##            main    #198     +/-   ##
=======================================
+ Coverage   65.1%   65.3%   +0.2%     
=======================================
  Files         23      23             
  Lines       2458    2458             
  Branches     494     494             
=======================================
+ Hits        1600    1605      +5     
+ Misses       786     777      -9     
- Partials      72      76      +4     

Impacted Files	Coverage Δ
spopt/locate/base.py	97.9% <ø> (ø)
spopt/locate/coverage.py	100.0% <ø> (ø)
spopt/locate/p_center.py	100.0% <ø> (ø)
spopt/locate/p_median.py	100.0% <ø> (ø)
spopt/locate/util.py	100.0% <ø> (ø)
spopt/_version.py	33.8% <0.0%> (+1.5%)	⬆️

[jGaboardi]

If we are going to have spaghetti in the doc string examples, then we should probably also have in requirements.txt.

[jGaboardi]

Overall, great job @gegen07. One small addition needed, then I think we can merge.