docs: add Neovim to the list of editors (#6081)

packages/web/src/content/docs/tui.mdx

@@ -325,6 +325,7 @@ Popular editor options include:
 - `code` - Visual Studio Code
 - `cursor` - Cursor
 - `windsurf` - Windsurf
+- `nvim` - Neovim editor
 - `vim` - Vim editor
 - `nano` - Nano editor
 - `notepad` - Windows Notepad