refactor: Use haumea for filesystem-based module system for flake outputs

refactor: Use hyphen(`-`) for variable names & folder names(except Python), replace all unserscore(`_`) with hyphen(`-`).

home/base/core.nix

@@ -1,8 +1,8 @@
-{username, ...}: {
+{myvars, ...}: {
   # Home Manager needs a bit of information about you and the
   # paths it should manage.
   home = {
-    inherit username;
+    inherit (myvars) username;
 
     # This value determines the Home Manager release that your
     # configuration is compatible with. This helps avoid breakage