Determine the number of tiles necessary per pixel

[oubiwann]

Pixel area notes are here:

• https://github.com/hexagram30/map/blob/master/docs/distance-and-time.md

Consider ASCII rols/cols needed for:

• sidebar
• lower chat area
• actual world representation

With the last in hand, determine the area represented by a single character, and the calculate the area of the pane dedicated to world representation; this will be the tile size.

Moved from oubiwann/tech-reflects#2