OTB QGIS plugin documentation is outdated

Description

Since OTB 6.6 a new qgis plugin is available for qgis 3:

https://gitlab.orfeo-toolbox.org/orfeotoolbox/qgis-otb-plugin

The plugin is not installed by default anymore and the related documentation in otb cookbook should be updated to describe the current status of OTB integration in qgis with the last stable release of OTB:

https://www.orfeo-toolbox.org/CookBook/OTB-Applications.html#qgis-interface

Steps to reproduce

Describe as precisely as possible how to reproduce the bug. Try to isolate a minimal number of steps. Also describe reproducibility (always, random ...).

Configuration information

OS, OTB version or tag, information related to build (binaries, superbuild, system libs ...)