Update README and examples to reflect current API - #140

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/setup-python@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Unexpected input(s) 'allow-prereleases', valid inputs are ['python-version', 'cache', 'architecture', 'token', 'cache-dependency-path']