FIX: Documentation for for 0.14.1 change log

Missing code reference in change log documentation
Merge pull request #7769 from bashtage/doc-stata-fix

FIX: Documentation for for 0.14.1 change log
BUG: Fixed incorrect string length calculation when writing strings to Stata

Strings were incorrectly written using 244 character irrespective of the actual
length of the underlying due to changes in pandas where the underlying NumPy
datatype of strings is always np.object_, and never np.string_. Closes #7858