Minor tutorial fixes (#32014)

GitOrigin-RevId: f8bb36607d93ccd2f2a20e6216728789ee4b719e

docs/tutorial/index.mdx

@@ -11,7 +11,7 @@ Convex provides you with a fully featured backend with cloud functions,
 database, scheduling, and a sync engine that keeps your frontend and backend up
 to date in real-time.
 
-Today, In about **10 lines of code,** we'll build a backend that reads and
+Today, in about **10 lines of code,** we'll build a backend that reads and
 writes to the database and automatically updates all users in a chat app.
 
 After that we'll see how to connect to external services and setup your product
@@ -269,7 +269,7 @@ import { useQuery, useMutation } from "convex/react";
 
 export default function App() {
   // highlight-next-line
-  // Replace the `const message = ...` line with the following
+  // Replace the `const messages = ...` line with the following
   // highlight-next-line
   const messages = useQuery(api.chat.getMessages);