README: document new directory structure

Signed-off-by: James Calligeros <[email protected]>

Author: chadmed

README.md

@@ -2,6 +2,23 @@
 
 This is the [Asahi Linux documentation](https://asahilinux.org/docs/) repository.
 
+## Documentation structure
+Our documentation is organised into categories.
+
+- alt: Alternative operating system/Linux distribution support documentation
+  should go here.
+- fw: Documentation on vendor-controlled firmware and firmware interfaces should
+  go here.
+- hw: Any documentation related to hardware belongs here. This is further split
+  into subcategories:
+    - cpu: Application processor documentation
+    - devices: Documentation relating to specific Mac models
+    - peripherals: hardware found in Apple Silicon Macs but not the SoC itself
+    - soc: hardware blocks integrated into Apple Silicon SoCs
+- platform: Documentation that applies across the Apple Silicon platform
+- project: Project admin documents and stuff unrelated to hardware or software
+- sw: Documentation for non-firmware software
+
 ## Usage
 
 This is made with [MkDocs](https://www.mkdocs.org/). If you have mkdocs installed already, run `make build` to build the site, or `make test` to spin up a local webserver for review. If you don't, feel free to use our [container](https://github.com/AsahiLinux/docs/pkgs/container/mkdocs-asahi) with something like: