chore: refactored package function to support both :package and :desktop_package configs

### CHANGES

- Added support for `:desktop_package` configuration
- Replaced `case` statement with `cond` for better readability
- Improved handling of default package configuration
- Updated warning message for missing package config
- Simplified logic flow for package configuration selection

Author: masegraye

lib/deployment.ex

@@ -6,16 +6,19 @@ defmodule Desktop.Deployment do
   def package(rel \\ nil) do
     config = Mix.Project.config()
 
-    case config[:package] do
-      nil ->
+    cond do
+      config[:package] != nil ->
+        struct!(default_package(rel), config[:package])
+
+      config[:desktop_package] != nil ->
+        struct!(default_package(rel), config[:desktop_package])
+
+      true ->
         Logger.warning(
           "There is no package config defined. Using the generic Elixir App descriptions."
         )
 
         default_package(rel)
-
-      map ->
-        struct!(default_package(rel), map)
     end
   end