Scan read (#18)

* Scan read
* Apply suggestions from various code reviews
* Moved implementation notes to other sections
* Tweaked the readability of EST Client, NMOS Server and NMOS Client sections
* Capitalization
* Consistent BRSKI ref
* Rephrase requirement that prohibits EST Servers from requesting HTTP-based auth
* Move normative sentences out of informative section
* Remove normative language key word from informative diagrams
* Make API endpoint requirements consistent with 'EST Server-Side Key Generation' section

Co-authored-by: Chris Mc <[email protected]>
Co-authored-by: jonathanthorpe-sony <[email protected]>
Co-authored-by: Simon Lo <[email protected]>
Co-authored-by: Jonathan Thorpe (Sony) <[email protected]>
Co-authored-by: Peter Brightwell <[email protected]>
Co-authored-by: JamesGibo <[email protected]>