QueryLimitConstraint
A QueryLimitConstraint is used to limit the number of documents returned by
a Firestore query.
QueryLimitConstraints are created by invoking limit or
limitToLast and can then be passed to {@link (query:1)} to create a new
query instance that also contains this QueryLimitConstraint.
class QueryLimitConstraint extends QueryConstraint {}
readonly type: "limit" | "limitToLast";