Update books/04_Numbers.tex

In Numbers 9:20, added the word "the" after "accordance with" and before "Lord's instruction" just before verse 21.

Before correction:
\v{20}There were times when the cloud remained over the tent for a number of days. They camped in accordance with the \divine{Lord}'s instructions and they traveled in accordance with \divine{Lord}'s instructions. 

After correction:
\v{20}There were times when the cloud remained over the tent for a number of days. They camped in accordance with the \divine{Lord}'s instructions and they traveled in accordance with the \divine{Lord}'s instructions.