docs: add README

README.md

@@ -0,0 +1,36 @@
+# Aἰθήρ
+
+> [*Aither*] as a whole neither came into being nor admits of destruction,
+> but is one and eternal, with no end or beginning of its total
+> duration, containing and embracing in itself the infinity of time ...
+>
+> -- Aristotle, *On the Heavens* [^1]
+
+Aether is a fully automated web server configured and deployed via
+**declarative package management**, powered by [NixOS](https://nixos.org).
+The declarative nature of NixOS allows for all aspects of the server's
+operation, including config files, software dependencies, and site content
+to be deployed and provisioned automatically.
+
+In short, it's my personal web server.
+
+## Deployment
+
+Aether is designed to separate deployment from the logical specification
+of the system, and thus to support any machine that can run NixOS. Currently,
+it is deployed physically to a
+[Raspberry Pi 5](https://wiki.nixos.org/wiki/NixOS_on_ARM/Raspberry_Pi_5)
+running a [modified UEFI bootloader](https://github.com/worproject/rpi5-uefi)
+to provide Linux support.
+
+## Module Checklist
+
+- [x] `forgejo.nix` - Code forge
+- [ ] `site.nix` - Personal website
+- [ ] `mail.nix` - Mail server
+- [ ] `backup.nix` - Automated backup system
+- [ ] `cachix.nix` - Nix build caching
+
+---
+
+[^1]: Adapted from [Book II.1](http://classics.mit.edu/Aristotle/heavens.2.ii.html).