package metadata: raise development status classifier to alpha

setup.py

@@ -45,7 +45,7 @@ setuptools.setup(
     ],
     classifiers=[
         # https://pypi.org/classifiers/
-        "Development Status :: 2 - Pre-Alpha",
+        "Development Status :: 3 - Alpha",
         "Intended Audience :: Developers",
         "License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)",
         "Operating System :: POSIX :: Linux",