fix: mobile menu for donation widget

layouts/partials/mobile-menu.html

@@ -0,0 +1,25 @@
+<ul class="menu menu--mobile">
+  <li class="menu__trigger">Menu&nbsp;▾</li>
+  <li>
+    <ul class="menu__dropdown">
+      {{ range $.Site.Menus.main }}
+        {{ if not .HasChildren }}
+          <li>
+            <a href="{{ .URL }}"
+               {{ with .Identifier }}data-identifier="{{ . }}"{{ end }}>
+               {{ .Name }}
+            </a>
+          </li>
+        {{ end }}
+      {{ end }}
+      {{ if and $.Site.Params.showLanguageSelector (len $.Site.Home.AllTranslations) }}
+        <hr />
+        {{ range $.Site.Home.AllTranslations }}
+          <li>
+            <a href="{{ .Permalink }}">{{ .Language.LanguageName }}</a>
+          </li>
+        {{ end }}
+      {{ end }}
+    </ul>
+  </li>
+</ul>