Clarify that FlatBuffers unions do not support scalars (#6416)
Clarify that FlatBuffers unions do not support scalars (#6416)

I mention that a common practice is to wrap the scalar value in a table
or a struct.

Signed-off-by: Juan Cruz Viotti <ee759b1936af4d7bd0d0e5363e6b1ea438e6a390@jviotti.com>
alexames/flatbuffers,DavadDi/flatbuffers,google/flatbuffers,google/flatbuffers,DavadDi/flatbuffers,google/flatbuffers,google/flatbuffers,evolutional/flatbuffers,google/flatbuffers,alexames/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,google/flatbuffers,evolutional/flatbuffers,DavadDi/flatbuffers,alexames/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,google/flatbuffers,google/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,google/flatbuffers,DavadDi/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,google/flatbuffers,DavadDi/flatbuffers,google/flatbuffers,alexames/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,google/flatbuffers,google/flatbuffers,google/flatbuffers,DavadDi/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,google/flatbuffers