accounts: recovery: add id card requirement for phone number change

Signed-off-by: Nicolas Froger <nico@cri.epita.fr>

docs/accounts/passwords.md

@@ -59,4 +59,5 @@ The messages can take a few minutes to arrive, be patient.
 If the phone number kept by the Bocal for password recovery is missing or wrong,
 you **must** send a ticket at
 [tickets@cri.epita.fr](mailto:tickets@cri.epita.fr) indicating your login and a
-french phone number.
+french phone number. You must also provide us a proof of your identity such as a
+picture of your ID card next to the current date.