Merge pull request #372 from JamesParrott/Option-C)-Multiple-file-package-(src/shapefile/{__init__,reader,writer,geoson,.}.py)

WIP.  Basic refactor into smaller modules

Author: JamesParrott

.github/workflows/run_checks_build_and_test.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Install mypy
       run: pip install mypy
     - name: Run mypy --strict
-      run: mypy --strict ./src/shapefile.py
+      run: mypy --strict ./src/shapefile
 
 
   build_wheel_and_sdist: