fix: use globalVariables for state.abb/state.name, regenerate docs

@importFrom does not work for base R lazy data objects — replaced with
utils::globalVariables() in the package file to suppress the R CMD check
NOTE. Removed the invalid @importFrom datasets tag from utils.R.

Also commits all man/ and NAMESPACE changes from devtools::document().

man/agresti_coull_interval.Rd

@@ -4,18 +4,22 @@
 \alias{agresti_coull_interval}
 \title{Calculate the Agresti-Coull interval}
 \usage{
-agresti_coull_interval(num, den, conf.level)
+agresti_coull_interval(num, den, conf.level = 0.95)
 }
 \arguments{
-\item{num}{a number of successes}
+\item{num}{number of successes}
 
-\item{den}{a number of trials}
+\item{den}{number of trials}
 
-\item{conf.level}{default 0.95, set the confidence interval to return}
+\item{conf.level}{default 0.95, confidence level for the interval}
 }
 \value{
-an interval
+three values forming the lower bound, observed proportion, and upper bound
 }
 \description{
 Calculate the Agresti-Coull interval
 }
+\examples{
+agresti_coull_interval(20, 40)
+agresti_coull_interval(2, 100, conf.level = 0.99)
+}