Add badges to the README. (#82)

* Add ReadTheDocs badge.

* Use latest ReadTheDocs for badge and update links.

* Update links to ReadTheDocs and Edgewall.

* Add GitHub actions badge.

* Add a PyPI version badge and switch to for-the-badge style.

* Switch ReadTheDocs badge to the for-the-badge style.

* Add Python versions and implementation badges for fun.

* Add Python implementations supported to classifiers.

README.md

@@ -0,0 +1,24 @@
+About Genshi
+============
+
+<!-- badges-start -->
+
+[![ReadTheDocs badge](https://readthedocs.org/projects/genshi/badge/?version=latest&style=for-the-badge)](https://genshi.readthedocs.org/)
+[![GitHub Actions Workflow Status](https://img.shields.io/github/actions/workflow/status/edgewall/genshi/tests.yml?branch=master&style=for-the-badge)](https://github.com/edgewall/genshi/actions/workflows/tests.yml)
+[![PyPI - Version](https://img.shields.io/pypi/v/genshi?style=for-the-badge)](https://pypi.org/project/genshi/)
+[![PyPI - Python Version](https://img.shields.io/pypi/pyversions/genshi?style=for-the-badge)](https://pypi.org/project/genshi/)
+[![PyPI - Implementation](https://img.shields.io/pypi/implementation/genshi?style=for-the-badge)](https://pypi.org/project/genshi/)
+
+<!-- badges-end -->
+
+Genshi is a Python library that provides an integrated set of
+components for parsing, generating, and processing HTML, XML or other
+textual content for output generation on the web. The major feature is
+a template language, which is heavily inspired by Kid.
+
+For more information please see:
+
+- [ReadTheDocs](https://genshi.readthedocs.org/)
+- [https://genshi.edgewall.org/](https://genshi.edgewall.org/)
+- the documentation in the `doc` directory.
+

setup.cfg

@@ -21,6 +21,8 @@ classifiers =
     Programming Language :: Python
     Programming Language :: Python :: 2
     Programming Language :: Python :: 3
+    Programming Language :: Python :: Implementation :: CPython
+    Programming Language :: Python :: Implementation :: PyPy
     Topic :: Internet :: WWW/HTTP :: Dynamic Content
     Topic :: Software Development :: Libraries :: Python Modules
     Topic :: Text Processing :: Markup :: HTML