updating sandbox sub-items to hopefully make them easier to read (#2994)
updating sandbox sub-items to hopefully make them easier to read (#2994)

* updating sandbox sub-items to hopefully make them easier to read

* updating sandbox attribute values data according to conversation with wbamberg and fscholz

chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data