Remove babel/polyfill ? #36
Description
The top line of src/index.js requires @babel/polyfill, this probably isn't ideal size-wise (see this from the babel docs). We should probably work out why it's here, is it for something specifically in this library or is it about trying to work around something upstream? And if babel is required we should probably move it to the build step in webpack or rollup etc.
Quickly scanning the code the optional chaining is the only thing that is new-ish, but even that has fairly wide support. So my gut feel is it can probably go.