Added information about Dendritic setups without flakes.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Co-authored-by: Victor Borja <vborja@apache.org>

- Layers are now automatically discovered from directories in
./dev/layers.

- Added an example vix layer which imports features from vic/vix repo.

- Added an example vix template that includes said layer to test it all.

- Layers are now automatically discovered from directories in
./dev/layers.

- Added an example vix layer which imports features from vic/vix repo.

- Added an example vix template that includes said layer to test it all.

Turns out our flake-parts module was accidentally treating systems as
"petSystem" instead of "perSystem" - which sounds adorable but sadly
doesn't compile!

In the spirit of Infrastructure as Cattle (not Pets), we should probably
be using perSystem anyway. But let's be honest, in a vegan DevOps world,
we'd call it "perTofuSystem" and our infrastructure would be both
cruelty-free AND reproducible! 🌱

Though I have to admit, the idea of each system having its own little
digital pet name was kind of endearing... RIP petSystem, you were too
pure for this world. 😿

Now our formatter can actually format things instead of just looking
cute in the config file.