Desktop: Resolves: Generate .deb installer for Joplin Desktop

[pedr]

Summary

Creates a .deb installer for Joplin Desktop.

By default, the electron-builder will use the package name as the name of the executable, so I add an executableName so package can be executed in CLI by running joplin instead of @joplinapp-desktop, for similar reason I also added the artifactName, without it the debian file would end-up on app-desktop/dist/@joplin/ instead of app-desktop/dist/.

Information about the package after installation

``` js@mint:~/Desktop/joplin/fork/packages/app-desktop/dist$ sudo apt show joplin Package: joplin Version: 3.2.4 Status: install ok installed Priority: optional Section: default Maintainer: Joplin Team Installed-Size: 867 MB Depends: libgtk-3-0, libnotify4, libnss3, libxss1, libxtst6, xdg-utils, libatspi2.0-0, libuuid1, libsecret-1-0 Recommends: libappindicator3-1 Homepage: https://github.com/laurent22/joplin#readme License: AGPL-3.0-or-later Vendor: Joplin Team Download-Size: unknown APT-Manual-Installed: yes APT-Sources: /var/lib/dpkg/status Description: Joplin for Desktop ```

Testing

1. On a Linux machine
2. Run yarn dist on app-desktop project
3. After the process is finished there should be one .Appimage and one .deb binary inside the app-desktop/dist folder
4. It should be possible to run sudo dpkg -i Joplin-${version}.deb to install the package on Debian derivated machines

[graphit0]

Just a heads up that in-app update from .deb version still downloads .AppImage package (not .deb one as expected).