added examples to graph

[Kryndlea]

added examples to docstrings

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.1%. Comparing base (e82d1be) to head (e92e77b).
Report is 15 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #745     +/-   ##
=======================================
+ Coverage   83.9%   85.1%   +1.2%     
=======================================
  Files        145     145             
  Lines      15583   15635     +52     
=======================================
+ Hits       13077   13309    +232     
+ Misses      2506    2326    -180     

Files	Coverage Δ
libpysal/graph/base.py	96.8% <ø> (ø)

... and 5 files with indirect coverage changes

[martinfleis]

Thanks!