Update lib/generators/react_on_rails/install_generator.rb

Co-authored-by: Alexey Romanov <[email protected]>

Author: justin808

lib/generators/react_on_rails/install_generator.rb

@@ -379,6 +379,7 @@ def create_typescript_config
             "esModuleInterop" => true,
             "allowSyntheticDefaultImports" => true,
             "strict" => true,
+            "noUncheckedIndexedAccess" => true,
             "forceConsistentCasingInFileNames" => true,
             "noFallthroughCasesInSwitch" => true,
             "module" => "esnext",