Add note regarding 401 Unauthorized Error

Add an explicit note stating if you receive 401 unauthorized error, you do not have permissions to use that token. See how to create a new token with appropriate permissions.

New user feedback!
Page: https://docs.influxdata.com/influxdb/cloud/security/tokens/view-tokens/
Feedback: I need a token to put into my code to enter data. influx auth list returns Error..... 401 Unauthorized What do i do to get my token?

Start with the token page at https://docs.influxdata.com/influxdb/cloud/security/tokens/view-tokens/ and review the linked guidance for creating tokens with appropriate permissions. Done means the page explicitly explains that a 401 Unauthorized error indicates insufficient token permissions and links readers to create a suitable token.

Written by the indexing model from the issue text.