update sso guide to local profile to use a profile other than default

[ykethan]

Describe the content issue:
A clear and concise description of what the content issue is. Is there content missing or is there incorrect content?

currently the guide provides the following information,
Make sure to set the profile name to default. Alternatively, remember the auto-generated profile name; you will need this later.

which can cause issue if they already have a default profile configured previously. Issue: aws-amplify/amplify-backend#1954

updating to guide to use a profile other than default would be helpful and also mitigate issues from folks coming from Gen 1

URL page where content issue is:
https://docs.amplify.aws/react/start/account-setup/#4-set-up-local-aws-profile