Improve setup metadata (#4458)

* Add relevant Trove classifiers

From full list: https://pypi.org/classifiers/

* Add all project URLs

* Add keywords

Copied from the repo's tags, minus "hacktoberfest"

* Add news entry for the change

* Use more explicit key for repo URL

news/improved-setup-py-metadata.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* Multiple new metadata fields in ``setup.py``
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>

setup.py

@@ -290,9 +290,31 @@ def main():
         author="Anthony Scopatz",
         maintainer="Anthony Scopatz",
         author_email="scopatz@gmail.com",
-        url="https://github.com/xonsh/xonsh",
+        url="https://xon.sh",
         platforms="Cross Platform",
-        classifiers=["Programming Language :: Python :: 3"],
+        project_urls={
+            "Changelog": "https://github.com/xonsh/xonsh/blob/main/CHANGELOG.rst",
+            "Repository": "https://github.com/xonsh/xonsh",
+            "Documentation": "https://xon.sh/contents.html",
+            "Issue tracker": "https://github.com/xonsh/xonsh/issues",
+        },
+        classifiers=[
+            "Development Status :: 4 - Beta",
+            "Environment :: Console",
+            "Intended Audience :: Developers",
+            "License :: OSI Approved :: BSD License",
+            "Natural Language :: English",
+            "Operating System :: OS Independent",
+            "Programming Language :: Python :: 3 :: Only",
+            "Programming Language :: Python :: 3.6",
+            "Programming Language :: Python :: 3.7",
+            "Programming Language :: Python :: 3.8",
+            "Programming Language :: Python :: 3.9",
+            "Programming Language :: Python :: 3",
+            "Topic :: System :: Shells",
+            "Topic :: System :: System Shells",
+        ],
+        keywords="python shell cli command-line prompt xonsh",
         packages=[
             "xonsh",
             "xonsh.ply.ply",