[vi] Change footer l10n from Home to Documentation

Addresses Vietnamese l10n strings described in #43068

Author: lyzlisa

content/vi/docs/home/_index.md

@@ -4,7 +4,7 @@ noedit: true
 cid: docsHome
 layout: docsportal_home
 class: gridPage gridPageHome
-linkTitle: "Home"
+linkTitle: "Tài liệu"
 main_menu: true
 weight: 10
 hide_feedback: true