title and text are required, invalid params when empty

[KoenWouters]

In https://developer.mozilla.org/en-US/docs/Web/API/Navigator/share it is not required to add text or title. But when using this polyfill we get an error invalid params.

share-api-polyfill/src/share.js

Line 259 in 68dc907

if (!data.title || typeof data.title !== 'string' || !data.text || typeof data.text !== 'string') {

Looks like this check shouldn't be here.