[Feature] add reverse api for array

[xihale]

Current State

The subpages API currently returns an array sorted by date, with the newest subpage appearing first. However, I want the newest subpage to be the last one processed in a loop. I’m unsure how to implement this, but I believe a reverse API could solve this issue.

Expectation

Calling $page.subpages().reverse() should return an array with the same subpages as $page.subpages(), but in reverse order.