Update changelog. Bump version (test release).

Author: brocaar

docs/config.toml

@@ -47,4 +47,5 @@ pygmentsUseClasses = true
     weight = 6
 
 [params]
-    version = "2.7.1"
+    version = "3.0.0-test.1"
+

docs/content/overview/changelog.md

@@ -18,13 +18,26 @@ description: Lists the changes per LoRa App Server release, including steps how
 
 The LoRa Gateway Bridge has been refactored to support multiple packet-forwarder
 backends. Next to the Semtech UDP packet-forwarder, support has been added to
-also support the Basic Station packet-forwarder.
+support the Basic Station packet-forwarder. This backend implements the 
+[Basic Station LNS protocol](https://doc.sm.tc/station/tcproto.html).
+
+#### Updated payload formats
+
+The uplink payload contains a `context` field, used to store gateway
+specific context data (like the internal counter).
+
+The downlink frame contains a `timing` field which can be either
+`IMMEDIATELY`, `DELAY` or `GPS_EPOCH`. Based on the `timing` value, an
+additional object must be given with the additional timing information.
+Refer to [Commands](https://www.loraserver.io/lora-gateway-bridge/payloads/commands/)
+for more details.
 
 ### Upgrading
 
 LoRa Gateway Bridge v3.0.0 include a couple of changes that are not backwards
 compatible. You need to re-generate the configuration file and update it where
-needed. Below a summary:
+needed. LoRa Gateway Bridge v3 is compatible with LoRa Server v2.7+.
+Below a summary:
 
 #### MQTT topics
 
@@ -49,7 +62,16 @@ Event types are: `up`, `stats` and `ack`.
 Commands are: `down` and `config`.
 
 Please note that LoRa Gateway Bridge v3 is compatible with LoRa Server v2.7+,
-but you will need to update the MQTT topics in your `loraserver.toml` file!
+but you will need to update the MQTT topics in your `loraserver.toml` file.
+Example snippet:
+
+{{<highlight toml>}}
+uplink_topic_template="gateway/+/event/up"
+stats_topic_template="gateway/+/event/stats"
+ack_topic_template="gateway/+/event/ack"
+downlink_topic_template="gateway/{{ .MAC }}/command/down"
+config_topic_template="gateway/{{ .MAC }}/command/config"
+{{</highlight>}}
 
 #### Backends