Declare support for Python 3.10 and update links (#2221)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.pre-commit-config.yaml

@@ -46,6 +46,8 @@ repos:
         args:
           - --min-py3-version
           - "3.4"
+          - --max-py-version
+          - "3.10"
   - repo: https://github.com/PyCQA/flake8
     rev: 3.9.2
     hooks:

setup.cfg

@@ -3,7 +3,7 @@ name = tox
 description = tox is a generic virtualenv management and test command line tool
 long_description = file: README.md
 long_description_content_type = text/markdown
-url = http://tox.readthedocs.org
+url = https://tox.readthedocs.io
 author = Holger Krekel, Oliver Bestwalter, Bernát Gábor and others
 maintainer = Bernat Gabor, Oliver Bestwalter, Anthony Asottile
 maintainer_email = tox-dev@python.org
@@ -26,6 +26,7 @@ classifiers =
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy
     Topic :: Software Development :: Libraries
@@ -35,6 +36,7 @@ keywords = virtual, environments, isolated, testing
 project_urls =
     Source=https://github.com/tox-dev/tox
     Tracker=https://github.com/tox-dev/tox/issues
+    Changelog=https://tox.readthedocs.io/en/latest/changelog.html
 
 [options]
 packages = find: