Iterate on workflow to compile binaries for all major OS<>arch combinations

[hendrikmaus]

This change-set iterates on the initial version of the workflow #57 and fixes the behavior observed and described in #175 (review).

Instead of compressing the compiled binaries before they are uploaded to GitHub, they are renamed to fj-host-<target>:

Furthermore, I adjusted the name of the workflow and some comments in the file.

[hannobraun]

Thank you, @hendrikmaus!

The commits look good, but we have a new problem: The execute permissions don't survive the upload/download process, without an archive to wrap them. (At least for the Linux/musl binary, but I suspect it's true for all the non-Windows ones.)

I'm tempted to just merge, as this pull request contains other improvements. Not sure if missing permissions are any better than the double-archive. Not much of a difference to me personally, but I suspect a less experienced user might be less confused by the double-archive.

Any suggestions?

[hendrikmaus]

I tried to explicitly retain the executable flag, but looks like we're out of luck.

On releases, we won't have these issues though. I reckon new users will either download the binary from a release or try to use a package manager to install. Hence, these "intermediary" binaries will only be used by contributors.

I'd stick with the current solution. However, we should write a little piece of documentation.

[hannobraun]

Makes sense, thanks Hendrik! I'm merging now, and will open an issue about documentation shortly.

[hannobraun]

Opened #180.