Version 0.4.0

New Features

• Consolidate API with Map-like interface (this.has(key), this.get(key), this.set(key, value) and this.delete(key)) and this.effect(fn); this being your custom element, usually called from within connectedCallback() in a class that extends UIElement
• Use an signal objects internally that duck-type instances of Signal.State and Signal.Computed of the early stage TC39 Signals Proposal, see https://github.com/tc39/proposal-signals
• Add types.d.ts definition
• Add more tests

Breaking Changes from v0.3.0

• No longer expose cause(value) and effect(fn) functions directly -> use the Map-like interface of UIElement
• Remove ability to return a cleanup function from effect callback functions -> just add cleanup code at the end of effect callback function
• Functions passed to this.set(key, fn) will be treated as derived or computed signals and are read-only -> if you want to replace the function using the same key, you have to this.delete(key) explicitly before you can create a new derived / computed signal