feat(treesitter): opt-out selection of the smallest node with flash.treesitter() by specifying autojump = false

[atusy]

current implementation of require("flash").treesitter() automatically selects the smallest node. However, this may cause unintentional scroll of the buffer like below.

This PR adds a functionality to opt-out the current behavior by respecting autojump configuration on require("flash").treesitter().