Using local storage to share data across multiple canvases

A collection of tips and tricks that might come in handy when working in p5.
What's the easiest and quickest way to have a p5 sketch re-start from where it last left off? Local Storage!
MDN web docs entry on Window.localStorage
p5 reference entry on the storeItem() method
p5 reference entry on the getItem() method
Article on options for storing data in the browser
Coding Train video on object-oriented programming in p5.js
What the Coding Train community has created based on this video
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