Add project URLs such as changelog and docs (gorakhargosh#833)

* add project urls such as changelog and docs

* Update setup.cfg

Co-authored-by: Mickaël Schoentgen <[email protected]>

Author: graingert

setup.cfg

@@ -1,3 +1,10 @@
+[metadata]
+project_urls =
+    Documentation=https://python-watchdog.readthedocs.io/en/stable/
+    Source=https://github.com/gorakhargosh/watchdog/
+    Issues=https://github.com/gorakhargosh/watchdog/issues
+    Changelog=https://github.com/gorakhargosh/watchdog/blob/master/changelog.rst
+
 [build_sphinx]
 source-dir = docs/source
 build-dir  = docs/build