Wire up typescript safety net around i18next

tsconfig.json

@@ -14,6 +14,7 @@
     "noUnusedLocals": true,
     "moduleResolution": "node",
     "declaration": true,
+    "resolveJsonModule": true,
 
     // TODO: Enable the following options later.
     // "forceConsistentCasingInFileNames": true,