update footnote doc; fix a bug in row_spec
diff --git a/R/footnote_marker.R b/R/footnote_marker.R
index df54339..beb1c4e 100644
--- a/R/footnote_marker.R
+++ b/R/footnote_marker.R
@@ -11,6 +11,11 @@
#' @param format Either `html` or `latex`. All functions here can read
#' default value from global option `knitr.table.format`.
#'
+#' @examples x <- mtcars[1:5, 1:5]
+#' colnames(dt)[1] <- paste0("mpg", footnote_marker_alphabet(2, "html"))
+#' rownames(dt)[2] <- paste0(rownames(dt)[2], footnote_marker_alphabet(1, "html"))
+#' footnote(knitr::kable(dt, "html"), alphabet = c("Note a", "Note b"))
+#'
#' @export
footnote_marker_number <- function(x, format) {
if (missing(format) || is.null(format)) {