### 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
throw new StrictDynamicMappingException(context.parser().getTokenLocation(), context.parent().fullPath(), currentFieldName);
        } else if (context.dynamic() == ObjectMapper.Dynamic.FALSE) {
            failIfMatchesRoutingPath(context, currentFieldName);
            
            context.parser().skipChildren();
        } else {
            Mapper dynamicObjectMapper;
            if (context.dynamic() == ObjectMapper.Dynamic.RUNTIME) {
                
                
                dynamicObjectMapper = new NoOpObjectMapper(currentFieldName, context.path().pathAsText(currentFieldName));
            } else {
                dynamicObjectMapper = DynamicFieldsBuilder.createDynamicObjectMapper(context, currentFieldName);
            }
            if (context.parent().subobjects() == false) {
                if (dynamicObjectMapper instanceof NestedObjectMapper) {
                    throw new DocumentParsingException(
                        context.parser().getTokenLocation(),
                        "Tried to add nested object ["
                            + dynamicObjectMapper.simpleName()
                            + "] to object ["
                            + context.parent().name()
                            + "] which does not support subobjects"
                    );
                }
                if (dynamicObjectMapper instanceof ObjectMapper) {
                    
                    
                    
                    parseObjectOrNested(context.createFlattenContext(currentFieldName));