Protect LaTeX math in the HTML format:  see https://stackoverflow.com/q/54048265/2554330
diff --git a/NAMESPACE b/NAMESPACE
index ab0fb47..b247396 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -37,6 +37,7 @@
 export(usepackage_latex)
 export(xtable2kable)
 import(htmltools)
+importFrom(digest,digest)
 importFrom(glue,glue)
 importFrom(grDevices,col2rgb)
 importFrom(knitr,asis_output)
@@ -57,6 +58,7 @@
 importFrom(rvest,html_table)
 importFrom(scales,rescale)
 importFrom(stats,ave)
+importFrom(stringr,fixed)
 importFrom(stringr,str_count)
 importFrom(stringr,str_detect)
 importFrom(stringr,str_extract)