To Do:
- barchart zooming
- connect the zooming with the "create_wordcloud()" function -> from the zooming we need a name, a year and the steps (1, 5 or 10) for the function, so if anything is named or given an ID in the zooming progress: keep in mind that we need to connect it to the wordcloud function
- if a word was clicked: Show a new wordcloud depicting only the letters containing that word. Person- and Yearfilters should be applied as well but that requieres computing the tf-idf scores on the fly and I really don't know how to do that with javascript