feat(svelte): enable reactivity of options via svelte action

[kelvinsjk]

Checklist

• run pnpm format
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

Changes

• In order to allow for reactivity of the options object, we used a Svelte action to call the updateOptions method any time the options object is changed
• Since the Svelte action directive also supports onMount and onDestroy, have refactored the original onMount and onDestroy code into the Svelte action
• Added a condensed extract of the svelte example in the examples sub-folder into the README document to make it easier for someone installing from npm to immediately get going

[crashmax-dev]

LGTM