Require treesitter (NOTE: newer nvim makes treesitter bltin)

https://github.com/MeanderingProgrammer/render-markdown.nvim

https://github.com/OXY2DEV/markview.nvim

Require external view

https://github.com/iamcco/markdown-preview.nvim (uses Browser)

https://github.com/toppair/peek.nvim (uses Webview or Browser)