chore: add py.typed + registering it it pyptoject.toml to enable ext

mypy type hint check

pyproject.toml

@@ -47,6 +47,7 @@ where = ["src"]
 
 [tool.setuptools.package-data]
 "pychangelogfactory.data" = ["*.*"]
+"pysimpleini" = ["py.typed"]
 
 [project.urls]
 Homepage        = "https://chacha.ddns.net/gitea/chacha/pychangelogfactory"

src/pychangelogfactory/py.typed

@@ -0,0 +1 @@
+# PlaceHolder