Demo: add highchart

Change-Id: I1eb75c52b609c3dadb20d26c4203519b42e2ff03
diff --git a/examples/ids.Rmd b/examples/ids.Rmd
index adba99a..75f7ae0 100644
--- a/examples/ids.Rmd
+++ b/examples/ids.Rmd
@@ -3,7 +3,7 @@
 subtitle: "a demo"
 author: Marc Kupietz
 institute: "IDS Mannheim"
-date: "Mannheim, 2024-01-01"
+date: "Mannheim, 2023-10-08"
 output: 
   revealjs::revealjs_presentation:
     theme: ids
@@ -26,6 +26,9 @@
 
 ```{r setup, include=FALSE}
 knitr::opts_chunk$set(echo = FALSE)
+library(idsThemeR)
+library(highcharter)
+library(tidyverse)
 ```
 
 ## R Markdown
@@ -61,3 +64,21 @@
 plot(pressure)
 ```
 
+## Registered Users
+### (for COSMAS II and KorAP)
+
+```{r registrations, message=F, warning=F}
+registrierungen <-
+  read_tsv("http://www.ids-mannheim.de/cosmas2/projekt/intstats/registrierungen.csv") %>%
+  add_column(group = "registered users")
+
+  hc <- registrierungen %>%
+    hchart("line", hcaes(x=date, y=registered, group=group)) %>%
+    hc_add_theme(hc_theme_ids_light()) %>%
+    hc_yAxis(title=list(text="")) %>%
+    hc_xAxis(title=list(text="")) %>%
+     hc_legend(element_blank()) %>%
+    hc_size(height=500, width=900)
+  hc
+
+```