v8.8.1 Release

Updated the height of participant boxes to be the same within a diagram(s).
Used the same naming standard for participants across diagrams.
Set default font as "Verdana" - this is a true web font.
Increased the font size for participant and actors.
Update all diagrams to include a "white space" between HTTP code and description.
Included 'hide footbox'.
Correct misspellings of "commission" on SVG diagrams.
Decrease the width of sequence diagrams 63, 64, 65 to fit onto screen for gitbook generation.

Converted the following documents in Markdown format;
- JSON Binding Rules,
- Generic Transaction Patterns.
Created the following sequence diagrams required in the documents;
- figure63a.plantuml,
- figure64a.plantuml,
- figure65a.plantuml,
- figure66a.plantuml.
Updated the following sequence diagrams;
- figure63.plantuml,
- figure64.plantuml,
- figure65.plantuml,
- figure66.plantuml.
Version to 8.8.1.
Updated SUMMARY file to include new documents.