Update Navbar component and add logout functionality

.env.example

@@ -0,0 +1 @@
+DATABASE_URL=

src/lib/components/Navbar.svelte

@@ -62,8 +62,8 @@
     {/if}
     {#if user}
       <UserAvatar {user} />
-      <form method="post" use:enhance>
+      <form method="post" action="/" use:enhance>
-        <button class="btn btn-primary ml-4">Sign out</button>
+        <button class="btn btn-primary ml-4">Logout</button>
       </form>
     {/if}
   </div>

src/routes/+page.server.ts

@@ -13,6 +13,7 @@ export const load: PageServerLoad = async (event) => {
   };
 };
 
+// handle the logout action
 export const actions: Actions = {
   default: async (event) => {
     if (!event.locals.session) {