[Feature Request] Ability to set notification position offset

[protiumx]

Summary

A configuration could look like

require('notify').setup({
  offset = { x = 0, y = -1 }
})

it should affect the render like position_x = row + offset.y.

Usage

This will help users to move the notifications so that they don't shadow parts of the status line

[samhed]

+1 for this, is there any way we can achieve an offset with an on_open function or a custom renderer?