META: Have examples in all READMEs

[jpmckinney]

And then include them in docs with jsoninclude directive.

• charges (PPP)
• contract_suppliers Update guidance on contract suppliers and change contract signatories to additional signatories #86
• documentation_details (PPP) Documentation: Remove content that ought to be in standard #84
• finance (example in the PPP sample data)
• milestone_documents (nothing in 1.0, need new example)
• process_title (PPP)
• qualification (PPP)
• risk_allocation (PPP)
• shareholders (PPP)

We should ideally test that the example validates (see open-contracting/standard-maintenance-scripts#24)

[jpmckinney]

With the Extension Explorer, we don't want to use any Sphinx directives. However, having a separate example might be useful. We can see if (1, preferred) we can extract the example easily from a well-formatted readme (e.g. under an Example heading), or (2) if we ought to have a separate example file.

[jpmckinney]

We'll go with option (1) as we don't have an obvious solution for merging the example into the readme without adding an extra step for extension authors – and maintaining the same example in two places is otherwise a headache and creates room for misalignment.

[jpmckinney]

@duncandewhurst Do you remember any potential existing examples for the other 8 extensions without examples listed in the issue description?

The finance example looks a bit long, but I'd be happy to merge some shortened version.

[duncandewhurst]

We should be able to extract examples from the PPP sample data for charges, documentation_details, finance, qualification, risk_allocation, shareholders and (I think) process_title.

[jpmckinney]

I added examples for 6 extensions, created blocking issues for 2 extensions, and will create a follow-up issue for milestone documents, which had no readily available example.