[TODO] rename to created_at

[nfx]

See more context:

sandbox/metascan/metadata/metadata.go

Lines 13 to 18 in a89763e

	Author string `yaml:"author"`
	Date time.Time `yaml:"date"` // TODO: rename to created_at
	LastUpdated time.Time `yaml:"updated_at"`
	Tags []string `yaml:"tags"`
	Maturity inventory.Maturity
	URL string