Add example to 12.9.2 rectilinear measurement for microscopic-level measurement data (micro-, nano-, pico-)

[petervwyatt]

Clause 12.9.2 "Algorithm: Use of a number format array to create a formatted text string" includes a simple geospatial-like example for rectilinear measurement.

What is not clear is how these same PDF measurement and number format objects can be used at the microscopic level (e.g. for lithographic x-rays, medical images, electron microscope images, etc.) where units are micro-, nano-, pico-, etc. Are there any limitations with using extremely small numbers, or having the accepted units scale up and display correctly using the correct units (and not using very large numbers and small scales). Adding an example to illustrate this would be extremely helpful - including identifying any shortcomings.