fix: import Buffer before use

[achingbrain]

Importing node's Buffer class before use makes bundling apps simpler because when your target is an environment that doesn't have a Buffer global, you don't have to ensure you've mutated the global object to add Buffer support before @peculiar/webcrypto is loaded - you can just do it by configuring the module resolver with a polyfill instead and let the user load modules in whatever order they want.

This makes bundling react-native apps a bit simpler.

[achingbrain]

@microshine are there any changes you want made here or can this be merged?

[microshine]

NPM package v1.4.4 has been published 🎉

[achingbrain]

Awesome, thanks!