Insticator Bid Adapter: document audio media type support - #2

The adapter accepts audio, but the page listed only banner and video under
media_types, so a publisher had no documented way to configure an audio ad unit.

Add audio to media_types and an Audio parameters table covering the OpenRTB 2.6
Audio object (section 3.2.8) in spec order, following the style of the video
table above it.

The video table was short of the ORTB 2.6 pod fields the adapter accepts, and of
ext. Add podid, podseq, poddur, slotinpod, mincpmpersec, maxseq, rqddurs and ext.

Four bid param entries named something the adapter does not read. yob and gender
come from params.user, so a publisher following the table was setting a field
nothing reads; they become user.yob and user.gender. instl and pos are not bid
params at all and are dropped from that table. instl is read from ortb2Imp and is
listed with the first party data alongside rwdd; pos already has its own rows in
the banner and video tables.

banner.ext had no row of its own though the adapter reads it, so the banner table
gains one and is realigned to its header.

fpd_supported is added to the front matter. The adapter reads first party data
throughout and the body already carries the section describing which fields,
which is what the flag requires. That list omitted site.mobile and said nothing
about ext; each object's ext now sits in the list beside the object it belongs to.

The section opened by pinning first party data support to release 8.45. The list
now spans fields added well after that, so the qualifier is dropped rather than
moved to a release this has not landed in.

yob was typed as a string with a quoted example. The adapter forwards it
untouched and the exchange requires an int64, so a publisher following the table
got a 400 that dropped the whole bid request rather than the one field. The
module documentation in the adapter repo already typed it as an integer; both now
agree.

params.user.keywords, params.user.data and params.user.ext were undocumented, and
the first party data list omitted the ortb2Imp media type ext paths the adapter
now reads in preference to mediaTypes.