fix(website): preserve page context when switching language (#3178)

layouts/partials/navbar-lang-selector.html

diff --git a/layouts/partials/navbar-lang-selector.html b/layouts/partials/navbar-lang-selector.html
index f36f348..18b838e 100755
--- a/layouts/partials/navbar-lang-selector.html
+++ b/layouts/partials/navbar-lang-selector.html
@@ -17,8 +17,16 @@
 
 <div class="nav nav-tabs languagetab-contain " id="languageTabs" role="tablist">
   {{ range $langCode, $langURL := $languages }}
+  {{ $targetURL := $langURL }}
+  {{ if $langPage.Language }}
+    {{ range $langPage.Translations }}
+      {{ if eq .Language.LanguageName $langCode }}
+        {{ $targetURL = .RelPermalink }}
+      {{ end }}
+    {{ end }}
+  {{ end }}
   <a class="languagetab-btn nav-item nav-link {{ if eq $langCode $currentLangCode }}active{{ end }}"
-    href="{{ $langURL }}" role="tab" aria-selected="{{ if eq $langCode $currentLangCode }}true{{ else }}false{{ end }}">
+    href="{{ $targetURL }}" role="tab" aria-selected="{{ if eq $langCode $currentLangCode }}true{{ else }}false{{ end }}">
     {{ $langCode }}
   </a>
   {{ end }}