media: media-types.rst: fix type, small improvements

data conector -> connector

... -> etc.

'...' looked odd when my browser put the ... by itself on the next line, 'etc.'
is clearer IMHO.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>