Try your best to stick to ~80 char length lines (most IDEs have an option for displaying a marker at this length). Github loosely pays attention to this, and it's a good general rule to keep your lines from flying off the screen. I break that rule pretty often to keep from having a usually single line statement from being two or three smaller ugly lines, if anything it's a good habit to get into as it makes you rethink your wording or how you plan to manage variable interaction/naming.

For this line I would probably just bump it down near the 80 char mark and do another line under it. Check out my readme.MD files for an example of sticking to this rule to the end. This is mainly in opposition to the default which is to have lines that basically go on forever, so I figured to wrap at 80, which makes them pretty readable almost everywhere.