add comparison to similar tools

[vtjnash]

Advantages:

• Uniform support for FreeBSD, macOS, Linux, and Windows
• Designed for tool / scripting usage
• Can find a library in the dyld path (similar to which, doesn't require full path to shared library like the tools listed below)
• Fully recursive list of dependencies

Some similar tools include:

• ldd: linux and bsd only
• otool -L: not recursive, macOS only
• objdump -p: not recursive (grep NEEDED on linux and bsd, grep -C 2 LC_LOAD_DYLIB | tail -n 1 on macOS, grep 'DLL NAME:' on mingw64, elfdump -d` on solaris)
• rpm autodeps scripts: axe'd in 2014 (moved internal), not recursive (by design)
• rpmdeps --requires: opaque, custom to rpm, elf-only?