Fix typos in Readme.md and highcharter-helpers

Change-Id: I5e2ecf3cdbe391f1521a5383e2a525703905e00e
diff --git a/R/highcharter-helper.R b/R/highcharter-helper.R
index 929ac0a..29bdc5d 100644
--- a/R/highcharter-helper.R
+++ b/R/highcharter-helper.R
@@ -156,7 +156,7 @@
 #' Add KorAP search click events to highchart
 #'
 #' @description
-#' Adds on-click events to data points of highcarts that were constructed with
+#' Adds on-click events to data points of highcharts that were constructed with
 #' \code{\link{frequencyQuery}} or \code{\link{collocationScoreQuery}}. Clicks on data points
 #' then launch KorAP web UI queries for the given query term and virtual corpus in
 #' a separate tab.