restructure

- users/rin/default.nix -> users/rin.nix
- users/rin/home.nix +-> users/rin.nix
- users/rin/*.nix -> modules/user/*.nix
- users/rin/scripts/ -> scripts/
- hosts/winter/default.nix -> hosts/winter.nix
- hosts/winter/*.nix -> modules/system/*.nix

- modules are dynamically imported as sets for system and user

scripts/xinitrc

@@ -0,0 +1,11 @@
+if test -z "$DBUS_SESSION_BUS_ADDRESS"; then
+    eval $(dbus-launch --exit-with-session --sh-syntax)
+fi
+systemctl --user import-environment DISPLAY XAUTHORITY
+
+if command -v dbus-update-activation-environment > /dev/null 2>&1; then
+    dbus-update-activation-environment DISPLAY XAUTHORITY
+fi
+
+xrdb ${XDG_CONFIG_HOME}/xorg/xresources
+exec ${XDG_CONFIG_HOME}/xorg/xsession