Reed suggested edits to 07-mapping Mapping this standard to types of models

[cnreediii]

https://github.com/opengeospatial/ogc-modspec/blob/cnreediii-patch-1/sources/sections/07-mapping.adoc

Fixed typos, grammar.
Made use of "standard" and "specification" consistent
The current ModSpec does not use standard OGC requirements class and requirement templates. ModSpec existed prior to such templates. So I inserted a requirements class example and some requirements examples in a template.