Add Nix flake for development environment (#534)

Author: IrakliJani

.gitignore

@@ -8,4 +8,7 @@
 out/
 images/.DS_Store
 .DS_Store
-.env/
+.env/
+
+.direnv/
+.envrc

flake.lock

@@ -0,0 +1,48 @@
+{
+  description = "Nix flake for Lightdash Docs development environment";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      # This covers typical Linux and macOS architectures.x
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+
+      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
+    in
+    {
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = import nixpkgs {
+            inherit system;
+            config = {
+              allowUnfreePredicate =
+                pkg:
+                builtins.elem (nixpkgs.lib.getName pkg) [
+                  "graphite-cli"
+                ];
+            };
+          };
+        in
+        {
+          default = pkgs.mkShell {
+            name = "lightdash-docs-dev-shell";
+
+            buildInputs = with pkgs; [
+              nodejs
+              graphite-cli
+            ];
+          };
+        }
+      );
+    };
+}