[DISCUSS] IO Reference Documentation

[Stephen Mallette <sp...@gmail.com>]

I just added a new book to our compendium of documentation - IO Reference.

http://tinkerpop.apache.org/docs/3.2.3-SNAPSHOT/dev/io/#_io_reference

It provides lots of samples (especially around GraphSON which will be
helpful to GLVs i think) and some additional details that aren't in our
standard reference documentation, which is a bit more user facing whereas
this IO Reference is more for developers.I purposely didn't want to add
this content to our Reference Docs as it would just blow out the length of
it in a pretty big way. I probably need to polish up the Reference Docs now
a bit more in the context of this, but that can happen on the way through
code freeze.

I think there's more details I could add, but this is a good stopping point
for purposes of general review.