Add reasonable max for tuple types (fix #438)

[bcherny]

This diff adds a reasonably large maximum size for how many members we emit for bounded-size arrays.

Before, we'd emit whatever number was specified by maxItems unless a user opted out of this with the ignoreMinAndMaxItems option.

Now, we default to emitting a union of TypeScript tuples for arrays where maxItems - minItems > N, where N defaults to 20 and can be overridden with the maxItems option. We also emit JSDoc blocks for minItems and maxItems, to more explicitly annotate the intent behind the JSON-Schema.

Alternative approaches considered:

1. Do nothing. This DevX isn't great, as some users will see a cryptic OOM error and not know how to fix it.
2. Throw and suggest the user enables ignoreMinAndMaxItems if we detect too large a number of cycles when emitting tuple members. This is more explicit, but just looking at number of cycles isn't a reliable indicator of OOMs.