Update Awesome Co docs to contain correct rake namespace

What does this MR do and why?

Updates the documentation for the Awesome Co seeder to contain the proper rake namespace (now contained in the ee namespace).

See: !83656 (merged)

How to set up and validate locally

% bin/rake -T | grep gitlab:seed:awesome_co"
rake ee:gitlab:seed:awesome_co[co,namespace_id]                                                       # Seed test data for a given namespace

MR acceptance checklist

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