update footnote doc; fix a bug in row_spec
diff --git a/R/footnote.R b/R/footnote.R
index 8863327..5e9201f 100644
--- a/R/footnote.R
+++ b/R/footnote.R
@@ -26,6 +26,9 @@
 #' @param alphabet_title Section header for alphabet footnotes. Default is "".
 #' @param symbol_title Section header for symbol footnotes. Default is "".
 #'
+#' @examples x <- mtcars[1:5, 1:5]
+#' footnote(knitr::kable(dt, "html"), alphabet = c("Note a", "Note b"))
+#'
 #' @export
 footnote <- function(kable_input,
                      general = NULL,