Started the descriptions of fields in the README file.
Fixed typos and added some notes
Add metrics to enable deeper interogation of data
Change the bad name "Retina-ness" to "Display Quality"
Remove max and min OS version

This was redundant data, max an min can be generated form the os_version array.
Replace magic numbers with null

Removed magic number for geekbench_v3_single_core and geekbench_v3_multi_core and replaced with null.
Added stub files for all current devices.
Fix indentation
Change metric names as suggested
Change suffix to unit, remove need for prefix
Add CPU Die Size
Merge pull request #3 from danielctull-forks/master

Add metrics to enable deeper interogation of data.
Reformatted capabilities

`capabilities` is now a flat array of strings.