Fix/improve types for `Resource` and `For`/`Index`/`mapArray`/`indexArray`#590

Merged

ryansolid merged 2 commits intosolidjs:mainfrom

otonashixav:fix-some-types

Aug 3, 2021

Commits on Aug 2, 2021

remove undefined from Resource<T> extends Accessor<T | undefined>
otonashixav
committed
make For and Index also accept falsy values for the each prop
otonashixav
committed