`gcn-populate-select.php`: Added snippet to dynamically populate Select and Multi-Select fields from the options in a Select or Multi-Select field in a Notion database.

[veryspry]

Context

⛑️ Ticket(s): https://secure.helpscout.net/conversation/2713458510/71717?viewId=6987275

Summary

Adds a snippet to dymically populate Select and Multi-Select fields from Notion fields.

Note: relies on the changes in: https://github.com/gravitywiz/gc-notion/pull/8