Saving Comment Box text - no server side

See pdf for detail On screen active editing (not in codeview but in the pages’ html and being viewed) - I want a script or packet of scripts (head and/or body) that will allow me to add comments on a student data page which is simple html and with Highcharts graphs. - I want to insert code / scripts that will display a text box which I can edit into my live / open web pages and have it saved and will reload next time - no server: standalone, on a single computer (connected to data projector) - I’ll insert the components into my existing pages - some form of ‘save’ button either in the box or at bottom of page - saving changes: save to csv / xml ??? - I’m open to all suggestions that will give me this capacity