#50 Some matrices missing description

[Mark Dominus]

BP says:

> For some reason, some matrices did not get the
> "Legacy TreeBASE Matrix ID = " comment. (e.g. M180, M81, M183, M1623, etc).
>

[Mark Dominus]

"M81" in the details is a type; it should say M181. M81 is fine.

These are TB2 matrix ids, not tb1 matrix ids.