Also install examples and tests

Not sure if this is considered good practice. However, until we have a
better way to include examples / tests in the documentation, I believe
this does not do too much harm.

pyproject.toml

@@ -65,7 +65,7 @@ documentation = "https://cadet-process.readthedocs.io"
 "Bug Tracker" = "https://github.com/fau-advanced-separations/CADET-Process/issues"
 
 [tool.setuptools.packages.find]
-include = ["CADETProcess*"]
+include = ["CADETProcess*", "examples*", "tests*"]
 
 [tool.setuptools.dynamic]
 version = { attr = "CADETProcess.__version__" }