docs: add examples to docstrings

[RaczeQ]

Modules to fill:

• Embedders
  • [ ] Count
  • [ ] Contextual Count
  • [ ] GeoVeX
  • [ ] Gtfs2vec
  • [ ] Hex2vec
  • [ ] Highway2vec
• Joiners
  • [ ] Intersection
• Loaders
  • [ ] Gtfs
  • [ ] Geoparquet
  • [ ] OSM Online
  • [ ] OSM PBF
  • [ ] OSM Tile
  • [ ] OSM Way
• Neighbourhoods
  • [ ] Adjacency
  • [ ] H3
• Plotting
• Regionalizers
  • [ ] Administrative Boundary
  • [x] Geocode
  • [ ] H3
  • [ ] S2
  • [ ] Voronoi
• Geometry
• H3

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (ac33edc) 88.09% compared to head (e7121fe) 88.67%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #401      +/-   ##
==========================================
+ Coverage   88.09%   88.67%   +0.57%     
==========================================
  Files          66       66              
  Lines        2932     2932              
==========================================
+ Hits         2583     2600      +17     
+ Misses        349      332      -17     

Flag	Coverage Δ
macos-latest-python3.11	88.09% <100.00%> (+0.51%)	:arrow_up:
ubuntu-latest-python3.10	87.99% <100.00%> (+0.57%)	:arrow_up:
ubuntu-latest-python3.11	87.99% <100.00%> (+0.57%)	:arrow_up:
ubuntu-latest-python3.9	87.97% <100.00%> (+0.51%)	:arrow_up:
windows-latest-python3.11	88.16% <100.00%> (+0.57%)	:arrow_up:

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[RaczeQ]

TODO: incorporate https://docs.pytest.org/en/7.1.x/how-to/doctest.html into testing scripts