Calculate MD5 checksums for multiple files

Calculate MD5 cryptographic checksums.
More information: <https://ss64.com/osx/md5.html>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

md5 {{filename1}} {{filename2}}

click the source code to copy install md5 on any operating system with command-not-found.com