Template:Chess diagram alt text

This template takes 2 arguments:
 * is the cell number, eg "a1", "b8", etc.
 * is the icon reference, eg: "kd", "kl", "bl", etc

It produces alt text. Cells with content read like "b8 black king".

Empty cells - which are just spaces or "__" - have no alt text (they emit  to fit with alt text guidelines.