Explain the usage of msdi (Most Significant Digit Index)
Use D idiomatic style to remove the leading zeros
Don't ignore the final element
Fixed the bad math the algorithm has been performing up until now

It is not possible to divide each word independently. Each word in
the base-10 word array must be reduced by the divisor in order and
the remainder from each higher word must be carried over to each
respective lower word.

Care needs to be taken to correctly calculate the positional
information of the remainder when  transferring between words.