Add link to digitalocean access-token docs

Signed-off-by: Zadkiel Aharonian <hello@zadkiel.fr>

docs/reference/issuers/acme/dns01/digitalocean.rst

@@ -6,9 +6,13 @@ This provider uses a Kubernetes ``Secret`` Resource to work. In the
 following example, the secret will have to be named ``digitalocean-dns``
 and have a subkey ``access-token`` with the token in it.
 
+To create a Personnal Access Token, see `DigitalOcean documentation <https://www.digitalocean.com/docs/api/create-personal-access-token/>`_. 
+Handy direct link: https://cloud.digitalocean.com/account/api/tokens/new
+
+
 .. code-block:: yaml
 
    digitalocean:
      tokenSecretRef:
        name: digitalocean-dns
-       key: access-token
+       key: access-token