Allow ArrayBuffer as input

[razor-x]

Closes #191

[razor-x]

@sindresorhus Anything else you need for a merge / release?

[sindresorhus]

You also need to update the readme.

[razor-x]

Cool. I've updated all the spots that mentioned Uint8Array to include ArrayBuffer.

[razor-x]

I'm not familiar with typescript, any thoughts on the CI error :|

  index.test-d.ts:8:59
  ✖  8:59  Argument of type number[] is not assignable to parameter of type number.  
  1 error
npm ERR! Test failed.  See above for more details.
The command "npm test" exited with 1.

[sindresorhus]

@razor-x Read the error. ArrayBuffer accepts a length (number) argument, not an array.

[razor-x]

Thanks :) Your translation is much clearer.