Merge two PDFs into one with the default suffix "joined"

PDF merging utility based on pdfjam.
More information: <https://github.com/rrthomas/pdfjam-extras>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

pdfjoin {{path/to/file1.pdf}} {{path/to/file2.pdf}}

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