replace your partials/menu.html
with this:
<nav class="menu">
<ul class="menu__inner">
{{- $currentPage := . -}}
{{ range .Site.Menus.main -}}
{{- $icon := printf "<i data-feather=\"%s\"></i>" .Pre -}}
{{- $text := print $icon " " .Name | safeHTML -}}
<li><a href="{{ .URL | absLangURL }}">{{ $text }}</a></li>
{{- end }}
</ul>
</nav>
then put feather.min.js
file into static/js/feather.min.js