Spec styling and consistency issues

As mentioned here, there's some consistency issues with the non-normative parts of the spec. It would be great to get a thorough review of this. These proposed fixes are all editorial, not functional.

Examples of ways we can improve:

• consistent use of monospace to refer to types and glossary terms (adding more glossary terms if necessary)
• Consistent language examples: some examples are typescript others are java. I think unless the requirement specifically demands a particular language, we use choose one example language, or a consistent pseudo-code. I recommend Java because it's explicit, typed, and generally well-understood.
• consistent reference to types with spaces and in lower-case as described in the style guide (ex: flag metadata not flagMetadata)
• consistent links in non-normative text (link anything relevant)
• Consistent diagrams (I vote we use mermaid for everything). We have diagrams in the provider and hooks sections that are not mermaid.
• Consistent pluralization: now that there's multiple providers, we need to update some language which implies there's only one. This will impact normative sections, but not in a meaningful or breaking way.

cc @tcarrio

Start by reviewing the non-normative text and the provider and hooks sections linked in the issue, then compare examples, type references, links, diagrams, glossary terms, and pluralization against the style guide. Done means the specification uses consistent editorial conventions throughout, including consistent example language or pseudocode and diagrams.