Add py.typed file for enhanced type hinting (#838)

Fixes #781

* fix: add py.typed file

Comply with PEP 561 and enable type checkers.
Fixes #781.

* chore: add py.typed to package_data in setup.py

* Style fixes

Co-authored-by: Dan <14043624+delivrance@users.noreply.github.com>

setup.py

@@ -172,6 +172,9 @@ setup(
         "Documentation": "https://docs.pyrogram.org",
     },
     python_requires="~=3.6",
+    package_data = {
+        "pyrogram": ["py.typed"],
+    },
     packages=find_packages(exclude=["compiler*", "tests*"]),
     zip_safe=False,
     install_requires=requires,