Add various links on the PyPI project page (#1183)

* Add various links on the PyPI project page

Add links to the documentation, change log, source code and issue tracker
to the PyPI project page.

* Split strings as the linter expects max line lengths of 88

* Reformatted project url links

---------

Co-authored-by: Oliver Sauder <os@esite.ch>

Author: takis

setup.py

@@ -94,6 +94,15 @@ def get_package_data(package):
         "Topic :: Software Development :: Libraries :: Application Frameworks",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],
+    project_urls={
+        "Documentation": "https://django-rest-framework-json-api.readthedocs.org/",
+        "Changelog": (
+            "https://github.com/django-json-api/django-rest-framework-json-api/"
+            "blob/main/CHANGELOG.md"
+        ),
+        "Source": "https://github.com/django-json-api/django-rest-framework-json-api",
+        "Tracker": "https://github.com/django-json-api/django-rest-framework-json-api/issues",
+    },
     install_requires=[
         "inflection>=0.5.0",
         "djangorestframework>=3.13",