### 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
return mapper instanceof FieldMapper && ((FieldMapper) mapper).parsesArrayValue();
    }
    private static void parseNonDynamicArray(DocumentParserContext context, final String lastFieldName, String arrayFieldName)
        throws IOException {
        XContentParser parser = context.parser();
        XContentParser.Token token;
        while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
            if (token == XContentParser.Token.START_OBJECT) {
                parseObject(context, lastFieldName);
            } else if (token == XContentParser.Token.START_ARRAY) {
                parseArray(context, lastFieldName);
            } else if (token == XContentParser.Token.VALUE_NULL) {
                parseNullValue(context, lastFieldName);
            } else if (token == null) {
                throwEOFOnParseArray(arrayFieldName, context);
            } else {
                assert token.isValue();
                parseValue(context, lastFieldName);
            }
        }
    }
    private static void throwEOFOnParseArray(String arrayFieldName, DocumentParserContext context) {
        throw new DocumentParsingException(
            context.parser().getTokenLocation(),
            "object mapping for ["
                + context.parent().name()
                + "] with array for ["
                + arrayFieldName
                + "] tried to parse as array, but got EOF, is there a mismatch in types for the same field?"
        );