modify for MAP-Elite Algorithm

[yyh-sjtu]

By using MAP-Elite to manage archive from which the OpenEvolve get the parents for the next generations.
Use ["complexity"] as feature_dimensions, because if we use ["score", "complexity"], the effectiveness of Evolution degrade significantly, according to my test.

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[codelion]

if we only have 1 feature in map elites, is it even that useful? We should probably figure out the right features tha can help the MAP-Elites explore multiple behaviors?

[yyh-sjtu]

if we only have 1 feature in map elites, is it even that useful? We should probably figure out the right features tha can help the MAP-Elites explore multiple behaviors?

Yes, after test, I think 1 feature complexity at least doesn't cause evolution effectiveness degradation.
According to the experiment, if we use 'complexity' and 'score' as features, the evolution effectiveness becomes significantly worse. I think this is also easy to understand—'score' should not be used as a feature.
And I think other features should also be added.