Open to a third argument to keep the elements to split at?

Sometimes you want to keep the element that causes the split (i.e., that the iteratee evaluates to true), i.e.,

splitBy([1, 2, 3, "|", 4, 5, 6], val => val === "|", true); // [[1, 2, 3], ["|", 4, 5, 6]]
//                                                   ^^^^  NEW              ^^^ NEW

Would you be open to accepting a pull request that implements this? The third argument could be called keepSeparator or something?

从 splitBy 入口开始，检查 iteratee 当前如何确定边界。实现并验证 issue 中所示的第三个参数行为，确保匹配的分隔符保留在下一个块的开头。