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/README.md

@@ -9,10 +9,11 @@ This folder contains resources that is used for building or packaging the projec
 ### Packaging
 
 - `icons/icon.{icns,ico,inl,rc,svg}`: lite-xl icon in various formats.
-- `linux/org.lite_xl.lite_xl.appdata.xml`: AppStream metadata.
-- `linux/org.lite_xl.lite_xl.desktop`: Desktop file for Linux desktops.
-- `macos/appdmg.png`: Background image for packaging MacOS DMGs.
-- `macos/Info.plist.in`: Template for generating `info.plist` on MacOS. See `macos/macos-retina-display.md` for details.
+- `linux/com.lite_xl.LiteXL.appdata.xml`: AppStream metadata.
+- `linux/com.lite_xl.LiteXL.desktop`: Desktop file for Linux desktops.
+- `macos/dmg-cover.png`: Background image for packaging macOS DMGs.
+- `macos/Info.plist.in`: Template for generating `info.plist` on macOS. See `macos/macos-retina-display.md` for details.
+- `macos/lite-xl-dmg.py`: Configuration options for dmgbuild for packaging macOS DMGs.
 - `windows/001-lua-unicode.diff`: Patch for allowing Lua to load files with UTF-8 filenames on Windows.
 
 ### Development