README: mention fd-find in requirements (nvim-lua#1477)

Fixes nvim-lua#1476

Author: dam9000

README.md

@@ -23,7 +23,8 @@ If you are experiencing issues, please make sure you have the latest versions.
 
 External Requirements:
 - Basic utils: `git`, `make`, `unzip`, C Compiler (`gcc`)
-- [ripgrep](https://github.com/BurntSushi/ripgrep#installation)
+- [ripgrep](https://github.com/BurntSushi/ripgrep#installation),
+  [fd-find](https://github.com/sharkdp/fd#installation)
 - Clipboard tool (xclip/xsel/win32yank or other depending on the platform)
 - A [Nerd Font](https://www.nerdfonts.com/): optional, provides various icons
   - if you have it set `vim.g.have_nerd_font` in `init.lua` to true