Docs: Java example bug

[robfig]

Cool project - I'm evaluating it for replacing some protobuf usage in some high performance corners of an existing system.

Tiny documentation bug on this page: https://google.github.io/flatbuffers/md__java_usage.html

It says

FlatBufferBuilder fbb = new FlatBufferBuilder();

but that constructor does not seem to exist -- I have to supply an initial size for the buffer.

[Jiboo]

The FlatBufferBuilder constructor in CPP also takes an initial size, but it defaults to 1024. As Java doesn't support default values for parameters, maybe it would be better to add a constructor with no parameters in the Java class instead of doing the fix in the docs. https://github.com/google/flatbuffers/blob/master/include/flatbuffers/flatbuffers.h#L486 https://github.com/google/flatbuffers/blob/master/java/com/google/flatbuffers/FlatBufferBuilder.java#L49