Update command to set default organization in README

[gautambaghel]

Description

Example Output

PR Checklist

• Ensure you have changie installed for release notes prep.
• Ensure any command changes are sensitive to these global flags:
  • --json — Force machine readable output to stdout. Does not apply to stderr.
  • --markdown — Force markdown output to stdout. Does not apply to stderr.
  • --dry-run — Don't make any actual writes or other mutations. Describe what would have changed to stderr.
  • --quiet — Don't render output to stdout.
• Get the logging interface from the context and add debug logging for interesting conditions and nonfatal situations.
• Run make gen/screenshot if the root command output changes.
• Add the Autocomplete field to positional arguments and flags to assist shell autocomplete.
• Run changie new to prepare a new changelog entry for the next set of release notes.

[brandonc]

I think this got mixed up when the README was re-written by docs. The property is supposed to be default_organization