docs: improve README and add small improvement for usage

README.md

@@ -2,3 +2,27 @@
 
 Minimal devshell implementation using Modules.
 Inspired by [numtide/devshell](https://github.com/numtide/devshell).
+
+## Features
+
+- **fast**: due to the NixOS module system it's a bit slower than `pkgs.mkShell`, but only about 10% (still in the tens of milliseconds range)
+- **minimal**: only contains the bare minimum, the rest should be added with imported modules
+- **straight forward**: no toml (like numtide/devshell), no abstractions over Nix (like devenv), just a straight forward Nix lib
+
+## Usage
+
+Simple example:
+
+```nix
+let
+  # make sure to add 
+  #  inputs.devshell.url = "gitlab:rensa-nix/devshell?dir=lib";
+  # to your inputs
+  devshell = inputs.devshell.lib { inherit pkgs; };
+in
+  devshell.mkShell {}
+```
+
+## Docs
+
+See [docs](https://devshell.rensa.projects.tf)

docs/usage.md

@@ -5,6 +5,12 @@
 The absolute minimum to get started:
 
 ```nix
+let
+  # make sure to add 
+  #  inputs.devshell.url = "gitlab:rensa-nix/devshell?dir=lib";
+  # to your inputs
+  devshell = inputs.devshell.lib { inherit pkgs; };
+in
   devshell.mkShell {}
 ```