pipe/filter: -l vs -1

[marwahaha]

In the class, several learners confuse the -l with the -1, especially in the serif'd fonts in the graphic.

I'm not sure if we can clarify the graphic, or at least give a few tips in the lesson or instructor guide that -l is NOT -1.

:)

[gcapes]

I've also had a few questions on this. The font could certainly make the distinction clearer. For programming, this is a useful font-selection criteria, along with slashed zeros to distinguish 0 and O. The font is probably something for the styles repository though?

[gdevenyi]

The graphics are pretty old, doubtful it's been standardized. Welcome a PR that fixes the fonts

[colinmorris]

Another alternative would be to use the long form of the option, --lines.