Support decoding timeseries Thresholds from YAML

[K-Phoen]

grabana/timeseries/timeseries.go

Lines 270 to 277 in 092b4d3

	// Thresholds configures the thresholds for this time series.
	func Thresholds(options ...threshold.Option) Option {
	return func(timeseries *TimeSeries) error {
	threshold.New(&timeseries.Builder.TimeseriesPanel.FieldConfig, options...)
	return nil
	}
	}

[rjnetskope]

@K-Phoen Need this feature

[K-Phoen]

Feel free to contribute :)