Add initial project files for MusicBrainz Missing Albums Finder

- Created .gitignore to exclude unnecessary files and directories.
- Added flake.nix for Nix package management and development environment setup.
- Introduced flake.lock to lock dependencies for reproducibility.
- Implemented main.py script to identify missing albums on MusicBrainz from Deezer releases for artists monitored in Lidarr, including functionality for generating submission links.

flake.nix

@@ -0,0 +1,37 @@
+{
+  description = "Lidarr to MusicBrainz Missing Albums Finder";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        pythonEnv = pkgs.python3.withPackages (ps: with ps; [
+          requests
+          python-dotenv
+        ]);
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs = [ pythonEnv ];
+          shellHook = ''
+            echo "Python environment ready!"
+            echo "Run: python main.py"
+          '';
+        };
+
+        packages.default = pkgs.writeShellApplication {
+          name = "lidarr-musicbrainz";
+          runtimeInputs = [ pythonEnv ];
+          text = ''
+            python ${./main.py} "$@"
+          '';
+        };
+      }
+    );
+}
+