[enhancement]: offer to contribute support for pfSense and RedSeal

# Add support for pfSense and RedSeal

Hello!

My company develops live training environments, and we recently needed to use both pfSense and RedSeal in our ranges. Unfortunately, our automation platform requires cloud-init, which at the time did not support these distros.

Out of necessity, we forked the project and implemented our own distro/renderer support for these platforms. The implementations are currently “rough-and-ready” (time constraints!), but they are functional and have been tested internally.

We would like to contribute this work back to the community. If we round out any missing features, add tests, and ensure compliance with project guidelines, would there be interest in accepting contributions to officially support pfSense and RedSeal?

- [RedSeal](https://github.com/uki-code/cloud-init/tree/feat/redseal)
- [pfSense](https://github.com/uki-code/cloud-init/tree/feat/pfsense)

If so, I can start work on bringing these branches up to date, aligning with the project coding standards, etc.

Thanks for your time and for maintaining such a valuable project!