Fix table formatting

[lmz]

These aren't rendering correctly.

https://github.com/osplanning-data-standards/dyno-demand/blob/master/files/trip_list.md

[ddorinson]

FYI to @lmz : my latest pull request (#10) includes layout fixes for this. I figure that merging it is way down on the stack vs. other technical issues right now, but LMK if I missed any glitches you were seeing on your side.