Update thumbnail component

- Pass in img size to help with load times and reduce layout shifts.
- Rename gameProjectThumb.svelte to thumbnail.svelte.

src/routes/index.svelte

@@ -1,20 +1,21 @@
 <script>
     import {onMount} from 'svelte';
-    import Thumb from '../components/gameProjectThumb.svelte'
+    import Thumb from '../components/thumbnail.svelte'
     import Banner from '../components/banner.svelte'
 
     let games = [
         {
             name: "Sirius",
             link: "./sirius",
-            thumb: "https://placehold.it/600x300",
+            img: "https://placehold.it/600x300",
+            size: { width: 600, height: 300 },
             description: "A 2D game about a wannabe space captain exploring the galaxy.",
-            imgClass: "img-fluid mb-3 mb-md-0"
         },
         {
             name: "Quartz",
             link: "./sirius",
-            thumb: "https://placehold.it/600x300",
+            img: "https://placehold.it/600x300",
+            size: { width: 600, height: 300 },
             description: ""
         }
     ]