fix typos in user manual
fix typos in user manual

Signed-off-by: Albert Cohen <73a0868e3038e0ec3c51dfdde902fd3aeb902a59@inria.fr>
Signed-off-by: Sven Verdoolaege <235c10dd23b819f81cdc9756a251746bc184cab6@gmail.com>

Meinersbur/isl,nicolasvasilache/isl,inducer/isl-mirror,nicolasvasilache/isl,PollyLabs/isl,nicolasvasilache/isl,PollyLabs/isl,Meinersbur/isl,nicolasvasilache/isl,nicolasvasilache/isl,PollyLabs/isl,Meinersbur/isl,Meinersbur/isl,inducer/isl-mirror,PollyLabs/isl,PollyLabs/isl,inducer/isl-mirror,inducer/isl-mirror,inducer/isl-mirror