Rendering issues related to file_types in Neovim 0.12

[solomonwzs]

Hello.

My config was like this:

local has, render = pcall(require, "render-markdown")
if has then
  render.setup({file_types = {"markdown", "chat"}})
end
vim.treesitter.language.register("markdown", "chat")

and here was a markdown file sample:

# 123

`hello`
**world**

It was ok when I set filetype to markdown:

If I call :set filetype=chat to set the filtype to chat, 123 was rendered correctly, but hello and world were not.

The issue occurred after I upgraded Neovim to version 0.12 and switch branch of nvim-treesitter from master to main. It was working normally in version 0.11.