### 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
context,
                        name,
                        dateTimeFormatter,
                        () -> strategy.newDynamicDateField(context, name, dateTimeFormatter)
                    );
                    return;
                }
                createDynamicField(
                    context,
                    name,
                    DynamicTemplate.XContentFieldType.STRING,
                    () -> strategy.newDynamicStringField(context, name)
                );
            } else {
                createDynamicField(
                    context,
                    name,
                    DynamicTemplate.XContentFieldType.STRING,
                    () -> strategy.newDynamicStringField(context, name)
                );
            }
        } else if (token == XContentParser.Token.VALUE_NUMBER) {
            XContentParser.NumberType numberType = context.parser().numberType();
            if (numberType == XContentParser.NumberType.INT
                || numberType == XContentParser.NumberType.LONG
                || numberType == XContentParser.NumberType.BIG_INTEGER) {
                createDynamicField(
                    context,
                    name,
                    DynamicTemplate.XContentFieldType.LONG,