refactor: Consolidate gp_libs/* to src/gp_libs.py

Including what would traditionally be placed in __about__.py

Author: tony

docs/conf.py

@@ -19,7 +19,7 @@
 
 # package data
 about: t.Dict[str, str] = {}
-with open(project_root / "gp_libs" / "__about__.py") as fp:
+with open(project_root / "src" / "gp_libs.py") as fp:
     exec(fp.read(), about)
 
 extensions = [

docs/developing.md

@@ -59,7 +59,7 @@ CI. See the configuration in `pyproject.toml` and `setup.cfg`:
 [poetry] handles virtualenv creation, package requirements, versioning,
 building, and publishing. Therefore there is no setup.py or requirements files.
 
-Update `__version__` in `__about__.py` and `pyproject.toml`::
+Update `__version__` in `src/gp_libs.py` and `pyproject.toml`::
 
     git commit -m 'build(gp_libs): Tag v0.1.1'
     git tag v0.1.1