How to integrate this into the SharePoint:
- Upload to public Document library
- Copy url of uploaded Document
- Add Script editor on specified Page
- Paste following content:
<script src="{url to script}" type="text/javascript"></script>
- Paste following content:
Or alternatively use the url to the script of GitLab:
https://raw.githubusercontent.com/aurelschwitter/ColoredCalendar/master/colorcalendar.js