AppImage should have arch in filename

[probonopd]

• Version: master

• Target: Linux AppImage

The recommended filename for an AppImage is AppName-1.0.1-x86_64.AppImage - this makes it easier for users to know which file to download. This would also allow me to do away with workarounds like this in automated AppImage generation.

[develar]

Our convention for all targets that arch for x64 is not included in the name. Because x64 should be default (e.g., as macOS supports only x64). When you build for ia32, arch will be specified in the name. But I think this convention should be changed according to AppImage format.

[develar]

Also, we use currently x64 (as node process.arch identifier). But I remember AppImage/AppImageKit#178 (comment) and

develar@ubuntu:~$ arch
x86_64

So, I don't like it, but... ok, we will use such suffix. Just want to be sure that it is really needed.

[develar]

What suffix should we use for ia32?