Change word "login" to "Sign in" (#100)

Author: benjie

@app/client/src/pages/index.tsx

@@ -135,8 +135,8 @@ const Home: NextPage = () => {
 
           <Title level={4}>What now?</Title>
           <Paragraph>
-            To get started, click "login" at the top right, then choose "Create
-            One" to create a new account.
+            To get started, click "Sign in" at the top right, then choose
+            "Create One" to create a new account.
           </Paragraph>
           <Paragraph>
             When you're happy, you can add database changes to{" "}