DOC: minor edits to Cookbook rst

Documentation/Cookbook/rst/Installation.rst

Documentation/Cookbook/rst/Monteverdi.rst

Documentation/Cookbook/rst/OTB-Applications.rst

Documentation/Cookbook/rst/recipes/optpreproc.rst

Documentation/Cookbook/rst/recipes/pbclassif.rst

Documentation/Cookbook/rst/recipes/residual_registration.rst

Documentation/Cookbook/rst/recipes/sarprocessing.rst

Documentation/Cookbook/rst/recipes/stereo.rst