### 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
context.parser().getTokenLocation(),
            "Field name cannot contain only whitespace: [" + context.path().pathAsText(currentFieldName) + "]"
        );
    }
    private static void throwEOF(ObjectMapper mapper, DocumentParserContext context) throws IOException {
        throw new DocumentParsingException(
            context.parser().getTokenLocation(),
            "object mapping for ["
                + mapper.name()
                + "] tried to parse field ["
                + context.parser().currentName()
                + "] as object, but got EOF, has a concrete value been provided to it?"
        );
    }
    private static void copyNestedFields(DocumentParserContext context, NestedObjectMapper nested) {
        if (context.isWithinCopyTo()) {
            
            
            
            
            return;
        }
        LuceneDocument nestedDoc = context.doc();
        LuceneDocument parentDoc = nestedDoc.getParent();
        IndexVersion indexVersion = context.indexSettings().getIndexVersionCreated();
        if (nested.isIncludeInParent()) {
            addFields(indexVersion, nestedDoc, parentDoc);
        }
        if (nested.isIncludeInRoot()) {
            LuceneDocument rootDoc = context.rootDoc();