Move jspdf to peer dependencies #201

From this version onwards, jspdf will have to be installed to use the pdf generation.

If you don't want to use pdf generation, but wish to use the chart menu options, you can remove the pdf button from the config:

const config = ref({
  userOptions: {
    show: true,
    buttons: {
      pdf: false, // hide the pdf button
    }
  }
})