feat(i18n): localize main page and enable i18n for homepage texts

- Updated index.tsx to use <Translate> and translate() for all main texts (title, subtitle, CTA, description) — now fully i18n-ready.
- Added new translation files (code.json, navbar.json, footer.json, etc.) to support Russian language for homepage and UI.
- Enables seamless language switching and correct translations of homepage elements.

website/i18n/ru/docusaurus-theme-classic/navbar.json

@@ -0,0 +1,18 @@
+{
+  "title": {
+    "message": "CherryPick",
+    "description": "The title in the navbar"
+  },
+  "logo.alt": {
+    "message": "CherryPick Logo",
+    "description": "The alt text of navbar logo"
+  },
+  "item.label.Docs": {
+    "message": "Документация",
+    "description": "Navbar item with label Docs"
+  },
+  "item.label.GitHub": {
+    "message": "GitHub",
+    "description": "Navbar item with label GitHub"
+  }
+}