* [DLAB-4240] Add documentation about PKI

* [DEVOPS] Add file extension, fixes & links to VITAM docs

Co-authored-by: Mathieu Leguay <mathieu.leguay@ouidou.fr>
Co-authored-by: Makhtar DIAGNE <makhtar.diagne@teamdlab.com>
Co-authored-by: Ro3034 <romaingordolo@gmail.com>