Not all ELF are for Linux

[jasperla]

Currently all ELF files are classified as runnable:linux. Would it be possible to change this to runnable:elf unless platform-specific strings are matched?

Currently ELF files contain quite some information to aid in correctly tagging them:

• ELF 32-bit LSB shared object, Intel 80386, version 1 (GNU/Linux), statically linked, no section header
• ELF 32-bit LSB executable, Intel 80386, version 1 (Solaris), dynamically linked, interpreter /usr/lib/ld.so.1, not stripped
• ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), static-pie linked, for OpenBSD, stripped
• ELF 32-bit LSB *unknown arch 0xa34* (NetBSD)

If this is a worthwhile direction I'd be happy to submit a PR.

[jasperla]

It turns out the latter part which includes the operating system isn't included in the magic variable. So instead I've opted for the more generic runnable:elf in #55

[psrok1]

Good point, PR merged and will be included in v2.0.0 release. Thanks!