feat: add default theme guide

Author: SayanthRock

themes/default/README.md

@@ -0,0 +1,27 @@
+# Default Theme Pack
+
+This is the default customer theme pack for ColorOS Themes Rock.
+
+## Style
+
+- Premium dark look
+- Desert Sand accent
+- Clean lock screen preview
+- Clean home screen preview
+- Minimal wallpaper set
+- Rounded visual style
+- Customer setup guide
+
+## Customer options
+
+| Area | Method | Status |
+|---|---|---|
+| Home wallpaper | Wallpaper settings | Safe |
+| Lock wallpaper | Wallpaper settings where supported | Safe |
+| Theme folder | Module folder test | Test required |
+| Icons | Launcher or OEM support | Test required |
+| Sounds | Manual setup where supported | Test required |
+
+## Note
+
+Add only original assets that you own or have permission to share.