Update README.md

Where do you go to test.

- [ ] a bigger project
  - [x] first subtask #1234
  - [ ] follow up subtask #4321
  - [ ] final subtask cc @mention
- [ ] a separate task

* SHA: a5c3785ed8d6a35868bc169f07e40e889087fd2e
* User@SHA: jlord@a5c3785ed8d6a35868bc169f07e40e889087fd2e
* User/Repository@SHA: jlord/sheetsee.js@a5c3785ed8d6a35868bc169f07e40e889087fd2e
* #Num: #26
* GH-Num: GH-26
* User#Num: jlord#26
* User/Repository#Num: jlord/sheetsee.js#26

this is for #1, by @b1thun3r :question: