add shell.nix and update README

.gitignore

@@ -3,6 +3,7 @@
 /venv/
 /build/
 **/*.egg-info/
+/dist/
 
 # makepkg
 /packaging/netcup-dns/

README.md

@@ -4,13 +4,25 @@ Update DNS A/AAAA records with your current external IP address using the netcup
 
 ## Installation
 
-On Arch Linux:
+Install release from PyPI (https://pypi.org/project/netcup-dns/):
+
+```shell
+pip install netcup-dns
+```
+
+Install release from TestPyPI (https://test.pypi.org/project/netcup-dns/):
+
+```shell
+pip install -i https://test.pypi.org/simple/ netcup-dns
+```
+
+Build and install on Arch Linux:
 
 ```shell
 make
 ```
 
-With `pip`:
+Build and install with `pip`:
 
 ```shell
 make install-pip

shell.nix

@@ -0,0 +1,13 @@
+# https://nixos.wiki/wiki/Python#Development_shell
+{ pkgs ? import <nixpkgs> {} }:
+let
+  my-python-packages = ps: with ps; [
+    requests
+    nc-dnsapi
+
+    # Build dependencies only.
+    build
+    twine
+  ];
+  my-python = pkgs.python3.withPackages my-python-packages;
+in my-python.env