Misc doc fixes
Fixes a typo I caught in the installation instructions, and a broken link.
I also added a subsection heading for the documentation about the pre-made conda environments, to emphasize that they are optional
Prochaine maintenance programmée : lundi 01/07
Pour plus d'informations : https://doc-si.inria.fr/display/SU/Gitlab
Fixes a typo I caught in the installation instructions, and a broken link.
I also added a subsection heading for the documentation about the pre-made conda environments, to emphasize that they are optional