📦 Add project_urls for pypi (Fixes #492)

Author: tony

setup.py

@@ -1,5 +1,6 @@
 """tmuxp lives at <https://github.com/tmux-python/tmuxp>."""
 import sys
+from collections import OrderedDict
 
 from setuptools import setup
 from setuptools.command.test import test as TestCommand
@@ -40,6 +41,13 @@ def run_tests(self):
     name=about['__title__'],
     version=about['__version__'],
     url=about['__github__'],
+    project_urls=OrderedDict(
+        (
+            ('Documentation', about['__docs__']),
+            ('Code', about['__github__']),
+            ('Issue tracker', about['__tracker__']),
+        )
+    ),
     download_url=about['__pypi__'],
     license=about['__license__'],
     author=about['__author__'],