Add flake.nix and direnv

Author: ToasterUwU

.envrc

@@ -0,0 +1,2 @@
+# shellcheck disable=SC2148
+use flake

.gitignore

@@ -0,0 +1,3 @@
+.direnv
+.venv
+flake.lock

flake.nix

@@ -0,0 +1,26 @@
+{
+  description = "Use `nix develop` to temp install everything you need for working on this project";
+
+  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
+        overlays = [ ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+      in
+      {
+        devShells.default = with pkgs; mkShell {
+          buildInputs = [
+            python3
+          ];
+          shellHook = "python3 -m venv .venv && source .venv/bin/activate && pip install -r requirements.txt";
+        };
+      }
+    );
+}