[ENH] Add flag_in_range function (resolves #708) - #1620

The deploy step encountered an error: remote: Permission to pyjanitor-devs/pyjanitor.git denied to github-actions[bot]. fatal: unable to access 'https://github.com/pyjanitor-devs/pyjanitor.git/': The requested URL returned error: 403 ❌

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: JamesIves/github-pages-deploy-action@4a3abc783e1a24aeb44c16e869ad83caf6b4cc23. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/