Clarify token usage instructions and reinforce one-time visibility

Author: MeelahMe

content/shared/influxdb3-cli/create/token.md

@@ -1,4 +1,7 @@
-The `influxdb3 create token` command creates a new authentication token.
+The `influxdb3 create token` command creates a new authentication token. This returns the raw token string. Use it to authenticate future CLI commands and API requests.
+
+>[!Important]
+>InfluxDB displays the raw token string only once. Be sure to copy and securely store it.
 
 ## Usage