docs: link Build Status to Tox workflow

Link to the same workflow that is checked for the badge.  Both because
it matches the badge status and because it's the one users are likely to
want to see.

Signed-off-by: Kevin Locke <[email protected]>

Author: kevinoid

README.rst

@@ -4,7 +4,7 @@ Project Template
 
 .. image:: https://img.shields.io/github/actions/workflow/status/kevinoid/python-project-template/tox.yml?branch=main&style=flat&label=build
    :alt: Build Status
-   :target: https://github.com/kevinoid/python-project-template/actions?query=branch%3Amain
+   :target: https://github.com/kevinoid/python-project-template/actions/workflows/tox.yml?query=branch%3Amain
 .. image:: https://img.shields.io/gitlab/pipeline-status/kevinoid/python-project-template.svg?branch=main&style=flat&label=build
    :alt: Build Status
    :target: https://gitlab.com/kevinoid/python-project-template/-/pipelines?ref=main