Remind user that generated password is in logs

Closes #446

src/browser/pages/login.html

@@ -25,7 +25,7 @@
       <form class="login-form" method="post">
         <div class="header">
           <div class="main">Welcome to code-server</div>
-          <div class="sub">Please log in below</div>
+          <div class="sub">Please log in below. Check code-server's logs for the generated password.</div>
         </div>
         <input class="user" type="text" autocomplete="username" />
         <input id="base" type="hidden" name="base" value="/" />