build(flake): adding the flake for this project

flake.nix

@@ -0,0 +1,52 @@
+{
+  description = "Shell for libasm project";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          name = "irc-42";
+          buildInputs =
+            with pkgs;
+            [
+              nasm
+              gcc
+              binutils
+              gnumake
+              lldb
+              coreutils
+              xxd
+              valgrind
+              clang-tools
+            ]
+            ++ (
+              if pkgs.stdenv.isLinux then
+                [
+                  strace
+                  valgrind
+                ]
+              else
+                [ ]
+            );
+
+          shellHook = ''
+              printf "\n\033[0;90mASM env loaded for: \033[38;5;220m${system}\033[0m\n"
+            '';
+        };
+      }
+    );
+}