refactoring to more granular flakes and modules

flakes/common/nix_modules/docker.nix

@@ -0,0 +1,17 @@
+{
+  config,
+  ...
+}:
+
+{
+  virtualisation.docker = {
+    enable = true;
+    autoPrune.enable = true;
+  };
+  users.extraGroups.docker.members = builtins.AttrNames config.users.users;
+  environment.shellAliases = {
+    dockerv = "docker volume";
+    dockeri = "docker image";
+    dockerc = "docker container";
+  };
+}