Small documentation change to "padic_add"
Small documentation change to "padic_add"

wbhart/flint2,fredrik-johansson/flint2,dsroche/flint2,dsroche/flint2,wbhart/flint2,jpflori/flint2,jpflori/flint2,jpflori/flint2,dsroche/flint2,wbhart/flint2,dsroche/flint2,fredrik-johansson/flint2,fredrik-johansson/flint2,jpflori/flint2