website: Document new options

website/source/docs/agent/options.html.markdown

@@ -40,6 +40,17 @@ The options below are all specified on the command-line.
   If this address is not routable, the node will be in a constant flapping state
   as other nodes will treat the non-routability as a failure.
 
+* <a id="atlas"></a>`-atlas` - This flag enables [Atlas](https://atlas.hashicorp.com) integration.
+  It is used to provide the Atlas infrastructure name and the SCADA connection.
+  This enables Atlas features such as the dashboard and node auto joining.
+
+* <a id="atlas_join"></a>`-atlas-join` - When set, enables auto-join via Atlas. Atlas will track the most
+  recent members to join the infrastructure named by `-atlas` and automatically
+  join them on start. For servers, the LAN and WAN pool are both joined.
+
+* <a id="atlas_token"></a>`-atlas-token` - Provides the Atlas API authentication token. This can also be provided
+  using the `ATLAS_TOKEN` environment variable. Required for use with Atlas.
+
 * <a id="bootstrap_anchor"></a>`-bootstrap` - This flag is used to control if a server is in "bootstrap" mode. It is important that
   no more than one server *per* data center be running in this mode. Technically, a server in bootstrap mode
   is allowed to self-elect as the Raft leader. It is important that only a single node is in this mode;
@@ -260,6 +271,16 @@ definitions support being updated during a reload.
 
 * `advertise_addr` - Equivalent to the [`-advertise` command-line flag](#advertise).
 
+* `atlas_acl_token` - When provided, any requests made by Atlas will use this ACL
+   token unless explicitly overriden. When not provided the `acl_token` is used.
+   This can be set to 'anonymous' to reduce permission below that of `acl_token`.
+
+* `atlas_infrastructure` - Equivalent to the [`-atlas` command-line flag](#atlas).
+
+* `atlas_join` - Equivalent to the [`-atlas-join` command-line flag](#atlas_join).
+
+* `atlas_token` - Equivalent to the [`-atlas-token` command-line flag](#atlas_token).
+
 * `bootstrap` - Equivalent to the [`-bootstrap` command-line flag](#bootstrap_anchor).
 
 * `bootstrap_expect` - Equivalent to the [`-bootstrap-expect` command-line flag](#bootstrap_expect).