Add shell.nix

env.nix

@@ -6,7 +6,12 @@
 # interpreter in the ‘Python: Select Interpreter’ command.
 #
 # To run Python with all dependencies available, use the wrapper script
-# env/bin/python.
+# env/bin/python. Alternatively, there's a shell.nix that allows you to
+# simply run
+#
+#   nix-shell
+#
+# to open a shell with the python environment added to $PATH.
 
 { nixpkgs ? <nixpkgs>, pkgs ? import nixpkgs {} }:
 

shell.nix

+{ nixpkgs ? <nixpkgs>, pkgs ? import nixpkgs {} }:
+(import ./env.nix { inherit pkgs; }).env