### 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/DocumentParser.java
}
        if (token == XContentParser.Token.START_OBJECT) {
            
            parser.nextToken();
        }
        innerParseObject(context);
        
        if (context.parent().isNested()) {
            copyNestedFields(context, (NestedObjectMapper) context.parent());
        }
    }
    private static void throwOnConcreteValue(ObjectMapper mapper, String currentFieldName, DocumentParserContext context) {
        throw new DocumentParsingException(
            context.parser().getTokenLocation(),
            "object mapping for ["
                + mapper.name()
                + "] tried to parse field ["
                + currentFieldName
                + "] as object, but found a concrete value"
        );
    }
    private static void innerParseObject(DocumentParserContext context) throws IOException {
        final XContentParser parser = context.parser();
        XContentParser.Token token = parser.currentToken();
        String currentFieldName = null;
        assert token == XContentParser.Token.FIELD_NAME || token == XContentParser.Token.END_OBJECT;
        while (token != XContentParser.Token.END_OBJECT) {
            if (token == null) {
                throwEOF(context.parent(), context);
            }