Is your feature request related to a problem? Please describe.
Add official support for the BSDs (e.g. OpenBSD, FreeBSD, and maybe macOS since it's a BSD descendant and acts similar to the BSDs).

This pretty much means:

• Fix bugs stopping Archey from running on BSD-based OSes.
• Add ASCII art for those OSes (will be fixed by [LOGOS] Adds {Free,Open}BSD + Updates Fedora, Ubuntu & Windows #78).
• Add functionality to entries to ensure they still work in BSD.

I think starting with OpenBSD/FreeBSD support is a good baseline since these OSes and their derivatives make up the majority of BSD users.

Describe the solution you'd like
Currently, the following modules access /proc filesystems and cause Archey to crash running on a BSD-based OS:

• Uptime - may will be fixed by [BUGFIX] Fix crash if no read permissions for /proc/uptime, and use fallbacks instead #66.
• Model - due to use of /proc/cpuinfo to check for a Raspberry Pi (fixed by a089b80).
• CPU - due to use of /proc/cpuinfo for CPU info (fixed by aab4046)
• RAM - due to fallback to /proc/meminfo since free is missing (fixed by a1d0f27).

These entries access information which is all contained within the sysctl command on BSD, therefore hopefully the fixes for these crashes are fairly easy.

These entries currently fail gracefully:

• CPU - Undetected, we'll have to go through sysctl (fixed by a3b6d36)
• Disk - occurs due to --args being an invalid format for the df implementation in BSD. Linked to [BUG] [DISK] [BUSYBOX] Entry is not detected #62, may be fixed by [WIP] Disk entry rework #67.
• RAM - free is still... missing here 🙄 (fixed by 2047505)
• Packages - the BSD package managers aren't present in the module 😃 (fixed by [PACKAGES] Add support for FreeBSD & OpenBSD #77).
• GPU (FreeBSD) - FreeBSD has pciconf but no pci-utils (so no lspci) (fixed by 162e608).
• Temperature - need to use sysctl (and enable temperature driver on FreeBSD) (fixed by 93de654).

I haven't got a DE or WM running under BSD, so the DesktopEnvironment and WindowManager entries may or may not work.

And, of course, we could do with some nice art to go with this support 😁. Of course, FreeBSD already has some suitable looking art on its boot screen:

Additional context

I'll do some experimentation with OpenBSD and FreeBSD and provide some more information on distro module output and sysctl values we will need.