refactor(build): use dmgbuild to create dmgs (#1664)

* refactor(appdmg): make dmgs with dmgbuild

* fix(appdmg.sh): typo

* refactor(appdmg.sh): don't generate config on the fly

* fix(dmgbuild): icon file

* fix(gitignore): dmgbuild settings

* chore(resources): update readme with new files

* chore(resources/macos): add missing newline

resources/macos/lite-xl-dmg.py

@@ -0,0 +1,28 @@
+# configuration for dmgbuild
+
+import os.path
+
+app_path = "Lite XL.app"
+app_name = os.path.basename(app_path)
+
+# Image options
+format = defines.get("format", "UDZO")
+
+# Content options
+files = [(app_path, app_name)]
+symlinks = { "Applications": "/Applications" }
+icon = "resources/icons/icon.icns"
+icon_locations = {
+    app_name: (144, 248),
+    "Applications": (336, 248)
+}
+
+# Window options
+background = "resources/macos/dmg-cover.png"
+window_rect = ((360, 360), (480, 380))
+default_view = "coverflow"
+include_icon_view_settings = True
+
+# Icon view options
+icon_size = 80
+text_size = 11.0