Including images in Ep. 2 Navigating the filesystem

[kmacvaug]

Hi there! I've noticed, like @enerammer did about the introduction, that the software carpentry version of the Unix Shell lesson has some more engaging and clear content. I recommend adding the images and some of the explanation (Home Directory Variation and Slashes) found on "Navigating Files and Directories" in the SW version https://swcarpentry.github.io/shell-novice/02-filedir/index.html to the Library Carpentry's second episode "Navigating the Filesystem" https://librarycarpentry.org/lc-shell/02-navigating-the-filesystem/index.html.