Added nix flake

Author: sjahreis

flake.nix

@@ -0,0 +1,55 @@
+{
+  description = "kotlin-atlassian-client - DEV-Environment";
+
+  inputs.nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.1.*.tar.gz";
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      javaVersion = 17;
+
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forEachSupportedSystem =
+        f:
+        nixpkgs.lib.genAttrs supportedSystems (
+          system:
+          f {
+            pkgs = import nixpkgs {
+              inherit system;
+              overlays = [ self.overlays.default ];
+            };
+          }
+        );
+    in
+    {
+      overlays.default = final: prev: rec {
+        jdk = prev."jdk${toString javaVersion}";
+        maven = prev.maven.override { jdk_headless = jdk; };
+        kotlin = prev.kotlin.override { jre = jdk; };
+      };
+
+      devShells = forEachSupportedSystem (
+        { pkgs }:
+        {
+          default = pkgs.mkShell {
+
+            MAVEN_HOME = "${pkgs.maven}/maven";
+
+            packages = with pkgs; [
+              gcc
+              jdk
+              kotlin
+              maven
+              patchelf
+              zlib
+            ];
+          };
+        }
+      );
+    };
+}