Add project_urls to setup.cfg

[skip ci]

setup.cfg

@@ -30,6 +30,11 @@ classifiers =
     Topic :: Software Development :: Libraries :: Python Modules
 author = Panda3D Team
 author_email = [email protected]
+project_urls =
+    Source=https://github.com/panda3d/panda3d
+    Tracker=https://github.com/panda3d/panda3d/issues
+    Documentation=https://www.panda3d.org/manual/
+    Funding=https://opencollective.com/panda3d
 
 [tool:pytest]
 testpaths = tests