chore: improve installation instructions and package metadata for PyPI release

setup.py

@@ -5,7 +5,7 @@ Setup script for devtools package.
 from setuptools import setup, find_packages
 
 setup(
-    name="devtools",
+    name="devtools-utils",
     version="0.1.0",
     packages=find_packages(),
     include_package_data=True,
@@ -29,7 +29,8 @@ setup(
     classifiers=[
         "Development Status :: 3 - Alpha",
         "Intended Audience :: Developers",
-        "License :: OSI Approved :: GPL License",
+        "License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)",
+        "Operating System :: OS Independent",
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",