[Packaging] README.md does not mention setting GitHub API token in user's crossbow repo settings #19249
Description
This environment variable must be configured in the Travis CI UI. I assume it's a similar story for Appveyor
Reporter: Wes McKinney / @wesm
Assignee: Krisztian Szucs / @kszucs
PRs and other links:
Note: This issue was originally created as ARROW-2878. Please see the migration documentation for further details.