Add usage example in readme

README.md

@@ -18,3 +18,48 @@ A `rustc` and `cargo` that can build for the Rust target `sbf-solana-solana`
 ## `anchor`
 
 The full Anchor CLI, including a functional build toolchain for the `anchor build` command.
+
+## Usage
+
+Define your `flake.nix` like the one below. It will install other necessary dependencies like
+
+- Nodejs and yarn
+- rustup with stable toolchain
+
+```nix
+{
+  description = "Solana and anchor flake";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs-unstable";
+    rust-overlay.url = "github:oxalica/rust-overlay";
+    solana.url = "github:arilotter/solana-flake";
+  };
+
+  outputs = { self, nixpkgs, rust-overlay, solana }:
+    let
+      pkgs = import nixpkgs {
+        overlays = [ rust-overlay.overlays.default ];
+        system = "x86_64-linux";
+      };
+    in
+    {
+      devShells.x86_64-linux.default = pkgs.mkShell {
+        buildInputs = [
+          pkgs.rustup
+          solana.packages.x86_64-linux.default
+          pkgs.nodejs_22
+          pkgs.yarn
+        ];
+
+        shellHook = ''
+          # Install the stable toolchain and set it as default
+          if ! rustup show | grep -q 'stable'; then
+            rustup install stable
+            rustup default stable
+          fi
+        '';
+      };
+    };
+}
+```