New Rule Suggestion / Rule amendment - in response to #903

In Issue #903 the rule in my opinion correctly throws on a += for simple defined arrays using the $var = @() method of defining an array to the var variable

I would suggest that a new rule is created that correctly identifies this method as being an expensive action and that a recommendation to use a fully defined Array collection would be a better suggestion, initially suggesting using a System.Collections.ArrayList

This rule should look for both @() & += and suggest converting these calls better scripting practices

首先阅读 issue #903 以及处理数组 += 的现有规则。确定 analyzer 应如何识别 @() 和 +=，然后定义所需的 recommendation 和 tests，以确认会建议完全定义的 collections，起初为 System.Collections.ArrayList。