Document specific options for dtype

In ref. to

I’ve not been able to find this nomenclature for pixel type [dtype] in the documentation
(Welcome to Orfeo ToolBox! — Orfeo ToolBox 8.0.1 documentation or
All Applications — Orfeo ToolBox 8.0.1 documentation)
despite -out image [dtype]
is stated in almost any command.This nomenclature might be obvious for users with
experience in the python module, but not for users of the command line.
Please include a section detailing how to set output format, data type and selected (input and output) bands.

Dear @alobo,

You are right, this requires more documentation. We will have to update that.

Julien :slight_smile: