fix(input): validate on input when field is touched

Closes #171

fix(choice): validate on store change (closes #170)

Co-authored-by: Manuel Sommerhalder <[email protected]>

feat(choice): update snapshots for tests

fix(choice,tests): add value default value, fix test

feat(components): pass attributes to HTML elements

BREAKING CHANGE: requires svelte >= 3.20.0
Closes #164

fix(deps,tests): update dependencies, fix tests

feat(components): add Input & Select label props (closes #129)

docs(readme): add demo link, fix example

BREAKING CHANGE: Release 1.0.0

feat(form): add more slot props to support custom fields

fix(choice): use empty array as multiple choice initial value