Fix missing-module-docstring

src/mailcow/__main__.py:1:0: C0114: Missing module docstring (missing-module-docstring)
src/mailcow/menu.py:1:0: C0114: Missing module docstring (missing-module-docstring)
src/mailcow/config.py:1:0: C0114: Missing module docstring (missing-module-docstring)
src/mailcow/globals.py:1:0: C0114: Missing module docstring (missing-module-docstring)
src/mailcow/__init__.py:1:0: C0114: Missing module docstring (missing-module-docstring)
src/mailcow/utils.py:1:0: C0114: Missing module docstring (missing-module-docstring)
src/mailcow/cli.py:1:0: C0114: Missing module docstring (missing-module-docstring)