add in TOC the file
update the introduction
add the reference about the section

Extended filemame are described in the OTB-Application section which is not the right place I think
No examples are provided,I have added two : one for reader and another for writer
I have added also a link about create_option of GDAL for GeoTIFF

BUG: EnableParameter method should be used to activate EmptyParameter in Python API in the ref documentation