Documentation examples: Make minimal or set to don't test

[adam3smith]

Package check runs all examples in function documentation by default. As a good pratice, let's make these examples as untaxing on the APIs as possible (i.e specific terms, short date ranges). Where that's not possible or desirable use dontrun{} or donttest{} as per https://stackoverflow.com/a/44997778/1483360

[mccallc]

Experimented with a few queries to find ones that pulled minimal results but still got at least one for APIs. More API-intensive queries were still shown in examples but put into \dontrun{} blocks. These were implemented in commit 7664e9bdd2b8660b9bc33d10d27607c2d52be5f0