docs: mention {#await} on non-Promise values short-circuiting to the fullfilled branch

Fixes sveltejs/kit#10882

Author: HoldYourWaffle

documentation/docs/02-template-syntax/03-logic-blocks.md

@@ -152,14 +152,16 @@ Since Svelte 4 it is possible to iterate over iterables like `Map` or `Set`. Ite
 {#await expression catch name}...{/await}
 ```
 
-Await blocks allow you to branch on the three possible states of a Promise — pending, fulfilled or rejected. In SSR mode, only the pending state will be rendered on the server.
+Await blocks allow you to branch on the three possible states of a Promise — pending, fulfilled or rejected.
+In SSR mode, only the pending branch will be rendered on the server.
+If the provided expression is not a Promise only the fulfilled branch will be rendered, including in SSR mode.
 
 ```svelte
 {#await promise}
 	<!-- promise is pending -->
 	<p>waiting for the promise to resolve...</p>
 {:then value}
-	<!-- promise was fulfilled -->
+	<!-- promise was fulfilled or not a Promise -->
 	<p>The value is {value}</p>
 {:catch error}
 	<!-- promise was rejected -->