### Description

Dynamic mappings can greatly help the getting started experience but they currently don't apply to all types, one example is `dense_vector`.

It's been suggested to automatically map float arrays as dense vectors when there are more than 100 values, or a heuristic along these lines.
server/src/main/java/org/elasticsearch/index/mapper/DynamicFieldsBuilder.java
static void createDynamicField(RuntimeField runtimeField, DocumentParserContext context) {
            context.addDynamicRuntimeField(runtimeField);