docs: update README with project structure and instructions

- Add detailed project structure breakdown, including modules, systems, and configurations.
- Update installation and update instructions for NixOS, macOS, and Home Manager.
- Replace outdated content with relevant examples and commands.

README.md

@@ -1,4 +1,57 @@
-Install a system via nixos-anywhere
+# NixOS Configuration
+
+A modular NixOS configuration setup for multiple systems.
+
+## Project Structure
+
+- `modules/`: Reusable NixOS/Darwin modules
+    - `common.nix`: Common module imports and definitions
+    - `nixos/`: NixOS-specific modules
+        - `home/`: Home Manager integration for NixOS
+        - `nix/`: Nix package manager configuration
+        - `nix-ld/`: Dynamic linking support
+        - `network/`: Network configuration modules
+            - `resolved/`: DNS resolution configuration
+        - `security/`: Security-related modules
+            - `ssh-host-keys/`: SSH host key management
+        - `services/`: Service configuration modules
+            - `base/`: Basic system configuration
+            - `gui/`: Graphical interface setup
+            - `homeprinter/`: Home printer support
+            - `podman/`: Container runtime
+            - `secureboot/`: Secure boot configuration
+        - `sgx/`: Intel SGX support
+            - `aesmd_dcap/`: SGX AESMD DCAP service
+            - `pccs/`: SGX Provisioning Certificate Caching Service
+        - `system/`: System configuration modules
+            - `auto-upgrade/`: Automatic system upgrades
+            - `limits/`: System resource limits
+            - `zram/`: ZRAM swap configuration
+        - `tools/`: Common tools configuration
+            - `direnv/`: Direnv integration
+            - `git/`: Git configuration
+        - `user/`: User account configuration
+        - `virtualization/`: Virtualization support
+    - `home/`: Home Manager modules
+        - `cli-apps/`: Command-line applications
+        - `gui/`: GUI application configuration
+        - `tools/`: User tools configuration
+        - `user/`: User preferences
+    - `darwin/`: Darwin-specific modules
+        - `home/`, `nix/`, `security/`, etc.
+- `systems/`: Individual system configurations
+    - `x86_64-linux/`: Linux systems on x86_64
+    - `aarch64-linux/`: Linux systems on ARM
+    - `x86_64-darwin/`: macOS systems on x86_64
+    - `aarch64-darwin/`: macOS systems on ARM
+- `homes/`: Home Manager configurations for each user/system
+- `lib/`: Helper functions and utilities
+- `overlays/`: Nixpkgs overlays
+- `packages/`: Custom packages
+
+## Using the Configurations
+
+### Install a system via nixos-anywhere
 
 ```bash
 $ nix run github:numtide/nixos-anywhere -- \
@@ -8,22 +61,21 @@ $ nix run github:numtide/nixos-anywhere -- \
 $ ssh -t root@hostname systemd-cryptenroll /dev/luksdev --wipe-slot=tpm2 --tpm2-device=auto --tpm2-pcrs=1,15
 ```
 
-nixos-rebuild remote git flake
+### Update NixOS system
 
 ```bash
 $ nixos-rebuild --use-remote-sudo -L --show-trace --refresh --flake git+https://git.hoyer.xyz/harald/nixcfg boot
 ```
-on darwin
+
+### Update macOS system
 
 ```bash
 $ darwin-rebuild -L --show-trace --refresh --flake git+https://git.hoyer.xyz/harald/nixcfg switch
 ```
 
-
-home-manager remote git flake
+### Update home-manager configuration
 
 ```bash
 $ nix --refresh run 'git+https://git.hoyer.xyz/harald/nixcfg' -- \
   switch -b backup --flake 'git+https://git.hoyer.xyz/harald/nixcfg'
 ```
-