[Linux] Add AppStream metadata

[probonopd]

By (optionally) adding AppStream metadata to AppImages, deb, and rpm files, applications could present themself more richly in app centers (e.g., GNOME Software, KDE Discover), AppImageHub, and app stores.

https://www.freedesktop.org/software/appstream/docs/chap-Quickstart.html#sect-Quickstart-DesktopApps

Important: Please be sure to check that the metainfo file passes appstreamcli validation.

[probonopd]

Hello @develar it looks like there is increasing demand for this, do you think it could be implemented anytime soon?

[ghisvail]

I second this. AppStream metadata should be forwarded upstream to avoid duplication of effort between packaging solutions. Without proper support in electron-builder however, it's difficult to motivate upstream projects to accept this file.

[GitSquared]

I've been willing to see this happening for so long i might end up adding a few bucks as bounty on this one. Please, we need this.

necroposting

[probonopd]

In the meantime, can that single file be added using extraResources or extraFiles?

https://github.com/electron-userland/electron-builder/wiki/Options