docs: refine autoincludes

docs/site/concepts/autoincludes.md

@@ -1,15 +1,33 @@
+# Auto-included Files
 
-Clan automatically imports the following files from a directory and registers them.
+Clan automatically imports specific files from each machine directory and registers them, reducing the need for manual configuration.
 
-## Machine registration
+## Machine Registration
 
-Every folder `machines/{machineName}` will be registered automatically as a Clan machine.
+Every folder under `machines/{machineName}` is automatically registered as a Clan machine.
 
-!!! info "Automatically loaded files"
+!!! info "Files loaded automatically for each machine"
 
-    The following files are loaded automatically for each Clan machine:
+The following files are detected and imported for every Clan machine:
 
-    - [x] `machines/{machineName}/configuration.nix`
-    - [x] `machines/{machineName}/hardware-configuration.nix`
-    - [x] `machines/{machineName}/facter.json` Automatically configured, for further information see [nixos-facter](https://clan.lol/blog/nixos-facter/)
-    - [x] `machines/{machineName}/disko.nix` Automatically loaded, for further information see the [disko docs](https://github.com/nix-community/disko/blob/master/docs/quickstart.md).
+- [x] `machines/{machineName}/configuration.nix`
+  Main configuration file for the machine.
+
+- [x] `machines/{machineName}/hardware-configuration.nix`
+  Hardware-specific configuration generated by NixOS.
+
+- [x] `machines/{machineName}/facter.json`
+  Contains system facts. Automatically generated — see [nixos-facter](https://clan.lol/blog/nixos-facter/) for details.
+
+- [x] `machines/{machineName}/disko.nix`
+  Disk layout configuration. See the [disko quickstart](https://github.com/nix-community/disko/blob/master/docs/quickstart.md) for more info.
+
+## Other Auto-included Files
+
+* **`inventory.json`**
+  Managed by Clan's API.
+  Merges with `clan.inventory` to extend the inventory.
+
+* **`.clan-flake`**
+  Sentinel file to be used to locate the root of a Clan repository.
+  Falls back to `.git`, `.hg`, `.svn`, or `flake.nix` if not found.