Update CDN link in docs

[lmiller1990]

Updated based on a issue someone asked on Stack Overflow

CDN link needs to also specify /dist/vue-rangedate-picker.min.js.

Test

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.13/vue.min.js">
</script>
<script src="https://unpkg.com/vue-rangedate-picker/dist/vue-rangedate-picker.min.js">
</script>

<div id="app">
  <vue-rangedate-picker
    @selected="onDateSelected" i18n="EN" format="YYYY-MM-DD hh:mm:ss">
  </vue-rangedate-picker>
</div>
</body>

<script>
document.addEventListener("DOMContentLoaded", () => {
  VueRangedatePicker.default.install(Vue)

  new Vue({
    el: "#app",
    methods: {
      onDateSelected() {
      }
    }
  })
})
</script>
</html>

Removing dist/vue-rangedate-picker.min.js from the CDN causes it not to work.

cc @khannedy is your org still maintaining this repo? Happy to help out with some of the PRs that need to be merged (been a while since anything was updated) and to clean up issues, or fix the CI. Been using this component a bit. Would be sad to see it not maintained anymore.