samples: wifi: radio_test: Fix missing doc for single domain

Fix missing Wi-Fi statistics doc include.

Signed-off-by: Chaitanya Tata <[email protected]>

Author: krish2718

samples/wifi/radio_test/single_domain/radio_test_subcommands.rst

@@ -8,3 +8,5 @@ Radio test subcommands
    :depth: 2
 
 .. include:: /includes/wifi_radio_test_subcommands.txt
+
+.. include:: /includes/wifi_radio_test_stats.txt