docs: clarify account name semantics

skills/bilibili-upload/scripts/examples/bilibili_commands.sh

@@ -1,14 +1,18 @@
 # login
 # Run this in a local interactive terminal.
 # If the terminal QR code is incomplete, open ./qrcode.png and scan that image.
-sau bilibili login --account creator
+account="account_a"
+# account_name is user-defined. One account_name maps to one account file.
+# You can prepare multiple account names and run them in parallel.
+
+sau bilibili login --account "$account"
 
 # check
-sau bilibili check --account creator
+sau bilibili check --account "$account"
 
 # upload video
 sau bilibili upload-video \
-  --account creator \
+  --account "$account" \
   --file ./videos/demo.mp4 \
   --title "Bilibili CLI Demo" \
   --desc "Bilibili CLI Demo" \