drug_type_concept_id description typo

[murphyke]

1. Minor typo, pedsnet v2 drug_type_concept_id:

A foreign key to a standard concept identifier of the type of drug exposure in the Vocabulary as represeneted in the source data

For consistency, there should be a period at the end, also.

1. Also for refills:

The number of refills after the initial prescrition

Also, again the terminating period.

1. Also for days_supply:

The number of days of supply the meidcation as recorded in the original prescription or dispensing record

Also the period.