add rad_development_python to environment and add update instructions

flake.lock

@@ -96,11 +96,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1722179153,
-        "narHash": "sha256-ZJ75T0GWpLI4hoaL+YxueHD2pXG+VYpYtPJdwbkERVs=",
+        "lastModified": 1722589669,
+        "narHash": "sha256-rxDnGBZK+Sp3df20nCCRrtQzRrJKxY7KtcYNPo5yfg8=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "dcfb2878c687e5eb5fcbc5116969c45c85be34e2",
+        "rev": "42015a129a2ae1cd43a44490e8235d2b24c8a2e2",
         "type": "github"
       },
       "original": {
@@ -137,11 +137,11 @@
         "treefmt-nix": "treefmt-nix"
       },
       "locked": {
-        "lastModified": 1721039874,
-        "narHash": "sha256-XANsG9GYHip8pxZpbqKf/YGv8tIa0xTh289Y+WNBNfw=",
+        "lastModified": 1722515463,
+        "narHash": "sha256-6FVPz1WzHak65xJQg8tRjVyFEWMesGxfskKaCxDUnRk=",
         "owner": "nix-community",
         "repo": "poetry2nix",
-        "rev": "d11c01e58587e5f21037ed6477465a7f26a32e27",
+        "rev": "8c25e871bba3f472e1569bbf6c0f52dcc34bf2a4",
         "type": "github"
       },
       "original": {