docs: fix typos and mistakes reported by Igor Stéphan
docs: fix typos and mistakes reported by Igor Stéphan

(during the PhD review process)

olzd/touist,olzd/touist,touist/touist,touist/touist,FredMaris/touist,olzd/touist,touist/touist,FredMaris/touist,FredMaris/touist,touist/touist