Improve macOS DMG drag-to-install layout

Author: fjh1997

Cargo.toml

@@ -34,9 +34,10 @@ generate-desktop-entry = true
 signing-identity = "-"
 
 [package.metadata.packager.dmg]
-window-size = { width = 640, height = 420 }
-app-position = { x = 170, y = 185 }
-application-folder-position = { x = 470, y = 185 }
+background = "assets/dmg/background.png"
+window-size = { width = 720, height = 460 }
+app-position = { x = 160, y = 220 }
+application-folder-position = { x = 560, y = 220 }
 
 [package.metadata.packager.deb]
 section = "utils"