Update documentation

Author: 42wim

website/content/docs/job-specification/service.mdx

@@ -150,6 +150,8 @@ service mesh][connect] integration.
     If a `to` value is not set, the port falls back to using the allocated host port. The `port`
     field may be a numeric port or a port label specified in the same group's network block.
 
+  - `alloc_ipv6` - Same as `alloc` but use the IPv6 address in case of dual-stack or IPv6-only.
+
   - `driver` - Advertise the port determined by the driver (e.g. Docker).
     The `port` may be a numeric port or a port label specified in the driver's
     `ports` field.
@@ -190,7 +192,7 @@ service mesh][connect] integration.
 - `tagged_addresses` `(map<string|string>` - Specifies custom [tagged addresses][tagged_addresses] to
   advertise in the Consul service registration. Only available where `provider = "consul"`.
 
-- `address_mode` `(string: "auto")` - Specifies which address (host, alloc or
+- `address_mode` `(string: "auto")` - Specifies which address (host, alloc, alloc_ipv6 or
   driver-specific) this service should advertise. See [below for
   examples.](#using-driver-address-mode) Valid options are:
 
@@ -200,6 +202,9 @@ service mesh][connect] integration.
     where no port mapping is necessary. This mode can only be set for services which
     are defined in a "group" block.
 
+  - `alloc_ipv6` - Identical as `alloc` but will pick the IPv6 address in case of
+    dual-stack or IPv6 only.
+
   - `auto` - Allows the driver to determine whether the host or driver address
     should be used. Defaults to `host` and only implemented by Docker. If you
     use a Docker network plugin such as weave, Docker will automatically use