Update to reveal.js 4.6.1

Change-Id: I566737c50b93dd8c094ad3c3fa59865260b3b4ba
diff --git a/inst/reveal.js-4.6.1/.gitignore b/inst/reveal.js-4.6.1/.gitignore
new file mode 100644
index 0000000..ba5aa84
--- /dev/null
+++ b/inst/reveal.js-4.6.1/.gitignore
@@ -0,0 +1,11 @@
+.idea/
+*.iml
+*.iws
+*.eml
+out/
+.DS_Store
+.svn
+log/*.log
+tmp/**
+node_modules/
+.sass-cache
\ No newline at end of file