Add a link to nerd-icons-completion in the README

[magthe]

Since you mention nerd-icons it's probably worth mentioning nerd-icons-completion as well.

@@ -142,6 +142,7 @@ A small set of packages related to `kind-icon`:
 - [all-the-icons](https://github.com/iyefrat/all-the-icons.el) is font-based icon library which can be used to enrich dired, neotree, the mode line and others with icons.
 - [all-the-icons-completion](https://github.com/iyefrat/all-the-icons-completion/) builds on `all-the-icons` to enrich minibuffer-based completion, including support for the excellent [marginalia](https://github.com/minad/marginalia) annotator. 
 - [nerd-icons](https://github.com/rainstormstudio/nerd-icons.el) makes it easy to use many of the same icons supported via SVG download within a single installed [NerdFont](https://www.nerdfonts.com).  See [the wiki](https://github.com/jdtsmith/kind-icon/wiki) for config.
+- [nerd-icons-completion](https://github.com/rainstormstudio/nerd-icons-completion) builds on `nerd-icons` to enrich minibuffer-based completion, including support for the excellent [marginalia](https://github.com/minad/marginalia) annotator. 

 ## Notes

[jdtsmith]

Done: 7b44f77.