Add availability_zone filed to INFO command (#228)

Signed-off-by: Binbin <[email protected]>

commands/hello.md

@@ -14,7 +14,8 @@ RESP2, although future version may default to RESP3.
 
 `HELLO` always replies with a list of current server and connection properties,
 such as: versions, modules loaded, client ID, replication role and so forth.
-(The availability_zone field only shows up when it is set in the configs.)
+The `availability_zone` field only shows up when it is set in the configs,
+see `availability-zone` config for more details, added in Valkey 8.1.
 
 When called without any arguments and its default use of RESP2
 protocol, the reply looks like this:

commands/info.md

@@ -55,6 +55,7 @@ lru_clock:3425456
 executable:/home/viktor/repos/valkey/src/./valkey-server
 config_file:
 io_threads_active:0
+availability_zone:
 listener0:name=tcp,bind=*,bind=-::*,port=6379
 
 # Clients
@@ -292,6 +293,7 @@ Here is the meaning of all fields in the **server** section:
 *   `executable`: The path to the server's executable
 *   `config_file`: The path to the config file
 *   `io_threads_active`: Flag indicating if I/O threads are active
+*   `availability_zone`: Inform Valkey of the Availability zone if running in a cloud environment, see `availability-zone` config for more details. Added in Valkey 8.0.
 *   `shutdown_in_milliseconds`: The maximum time remaining for replicas to catch up the replication before completing the shutdown sequence.
     This field is only present during shutdown.