readme: make it somewhat nicer

README.md

@@ -1,11 +1,56 @@
 # lsfg-vk-flake
-WIP! Nix flake to build the library for using Lossless Scaling's frame generation on Linux
+Nix flake for using [Lossless Scaling's frame generation on Linux](https://github.com/PancakeTAS/lsfg-vk)
 
-current state: builds and seems to be functional
+>[!IMPORTANT]
+> You need to have Lossless Scaling installed on Steam!
+> In case it is not installed on the default Steam drive, you may want to consider setting the environment variable ``LSFG_DLL_PATH=<ABSOLUTE_PATH_TO>/Lossless.dll``
 
-## manual install
+## Installation
-1. build the library with ``nix build``
+### System-wide (NixOS module)
-2. copy library and vulkan layer config to your ~/.local: ``cp -r result/* ~/.local/`` (check contents of result first!)
+This approach will install an implicit layer to ``/etc/vulkan/implicit_layer.d/``
-3. have lossless scaling installed on Steam or manually reference the DLL file using LSFG_DLL_PATH
 
-example usage command: ``LD_PRELOAD=~/.local/lib/liblsfg-vk.so LSFG_DLL_PATH=<POINT_ME_TO>/Lossless.dll ENABLE_LSFG=1 vkcube``
+Add this repository to your flake inputs, output function and module list:
+```nix
+inputs = {
+  ...
+  lsfg-vk-flake.url = "github:pabloaul/lsfg-vk-flake/main";
+  lsfg-vk-flake.inputs.nixpkgs.follows = "nixpkgs";
+}
+
+outputs = {nixpkgs, lsfg-vk-flake, ...}: {
+
+  nixosConfigurations.hostname = nixpkgs.lib.nixosSystem {
+    ...
+    modules = [
+      ...
+      lsfg-vk-flake.nixosModules.default
+    ];
+  };
+}
+```
+
+And then you should be able to enable this in your system config using:
+```nix 
+services.lsfg-vk.enable = true;
+
+# optional but recommended:
+environment.variables = { LSFG_DLL_PATH = "<ABSOLUTE_PATH_TO>/Lossless.dll"; }
+```
+
+### User install (manual)
+1. Build the library:
+  ``nix build``
+3. Create the following path in case it does not exist:
+  ``mkdir -p $HOME/.local/share/vulkan/implicit_layer.d`` 
+3. Symlink the build results to your $HOME/.local/
+  ``cp -ifrsv "$(readlink -f ./result)"/* $HOME/.local/``
+
+## Usage
+Run a Vulkan application with the environment variable ``ENABLE_LSFG=1`` set.
+
+Example: ``ENABLE_LSFG=1 vkcube`` and look for output like this in the terminal: lsfg-vk(...): ...
+
+You can also enable it per game on Steam by adding this to the launch options of a game like this: 
+  ``ENABLE_LSFG=1 %COMMAND%``
+
+There are many more options that can be set. Consult the original repository for further documentation.