Review mkdocs content to remove html which can be represented as markdown

[butler54]

Issue description / feature objectives

mkdocs is designed to render websites from markdown to minimise the amount of html that is manually created.
In reviewing the website a number of blocks have been introduced with raw HTML which can / should be avoided.

Caveats / Assumptions

• Do not remove content. Only remove HTML if an appropriate markdown substitution can be produced.

Completion Criteria