packaging metadata: link to the docs, issue tracker (#4345)

See https://github.com/pypi/warehouse/issues/5947
https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#urls

CHANGES.md

@@ -22,6 +22,9 @@
 
 <!-- Changes to how Black is packaged, such as dependency requirements -->
 
+- Packaging metadata updated: docs are explictly linked, the issue tracker is now also
+  linked. This improves the PyPI listing for Black. (#4345)
+
 ### Parser
 
 <!-- Changes to the parser or to version autodetection -->

pyproject.toml

@@ -93,8 +93,10 @@ blackd = "blackd:patched_main [d]"
 black = "black.schema:get_schema"
 
 [project.urls]
+Documentation = "https://black.readthedocs.io/"
 Changelog = "https://github.com/psf/black/blob/main/CHANGES.md"
-Homepage = "https://github.com/psf/black"
+Repository = "https://github.com/psf/black"
+Issues = "https://github.com/psf/black/issues"
 
 [tool.hatch.metadata.hooks.fancy-pypi-readme]
 content-type = "text/markdown"