README: update config file syntax

lumag · lumag · commit 5164ca92346a · 2023-09-23T16:50:11.000+03:00
Describe optional user/group/device mapping in the config file example.

Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
diff --git a/README b/README
@@ -43,6 +43,8 @@ devices:
     fastboot_set_active: true
 
   - board: evb2k
+    users:
+      - username
     console: /dev/ttyUSB0
     fastboot: abcdef3
     fastboot_set_active: true
