fix(render-markdown): remove redundant opts.file_types (#4506)

## Description
After
cb9a5e2412
there's no need for defining filetypes both in Lazy's `ft` and the
plugin's `opts.file_types`.
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## Related Issue(s)
None
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## Screenshots

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## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/plugins/extras/lang/markdown.lua

@@ -95,7 +95,6 @@ return {
   {
     "MeanderingProgrammer/render-markdown.nvim",
     opts = {
-      file_types = { "markdown", "norg", "rmd", "org" },
       code = {
         sign = false,
         width = "block",