Please allow desktop app to be built without requiring electron downloads.

When running yarn run package --platform linux --appVersion=${tagname#v} to build the desktop app (this seems to be handled in https://github.com/keybase/client/blob/master/shared/desktop/package.js) this really only has one option and that is to download prebuilt electron packages and build everything into some vendored binary distribution in shared/desktop/release/linux-x64/Keybase-linux-x64/

The only thing that is really needed is shared/desktop/release/linux-x64/Keybase-linux-x64/resources/app/, and from a distro packaging perspective it is far superior to e.g. package this as /usr/lib/keybase/ and use a launcher script that runs electron /usr/lib/keybase/ via a system electron installation.

I would appreciate if there was some (documented) method to simply generate the app directory without requiring all that extra work, and thereby simplifying the process of distro packaging for Keybase.

Start with shared/desktop/package.js and the existing output under shared/desktop/release/linux-x64/Keybase-linux-x64/. Determine how the packaging command can produce only resources/app without downloading or vendoring Electron; done means a documented build path generates that app directory for distro packaging.