Support other architectures

[chetbox]

e.g. arm64

In my use case I'm building an Electron app with Electron Forge to target a Raspberry Pi 4. This maker assumes x64 architecture.

I've added the platform and architecture to the output filename to ensure builds for different architectures have different names.

[chetbox]

I've tested this with electron-forge make --arch arm64 on a x64 Ubuntu machine. The resulting build run great on a Raspberry Pi.

You can test this PR with yarn add --dev https://github.com/chetbox/electron-forge-maker-appimage.git#refs/heads/other-archs