sddm-theme-fixes-cleanup-and-wlogout (#70)

- Removed theme.conf for sddm theme
- added alt background
- renamed default background into kebab case
- renamed sddm.yml into greeter.yml
- removed duplicates in greeter.yml

Reviewed-on: #70
Co-authored-by: Eriq Taing <eriq12@protonmail.com>
Co-committed-by: Eriq Taing <eriq12@protonmail.com>

recipes/components/dnf-module.yml

@@ -1,6 +1,6 @@
 modules:
   - from-file: dnf/multimedia.yml
-  - from-file: dnf/sddm.yml
+  - from-file: dnf/greeter.yml
   - from-file: dnf/hyprland.yml
   - from-file: dnf/environment.yml
   - from-file: dnf/applications.yml