Added ability to switch between light and dark mode

src/routes/+layout.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
 	import Toasts from "$lib/components/Toasts/Toasts.svelte";
+    import ThemeSwitcher from "$lib/components/ThemeSwitcher.svelte";
 </script>
 
 <style>
@@ -18,7 +19,7 @@
 
     nav {
         position: relative;
-        overflow:visible;
+        overflow: visible;
         display: flex;
         justify-content: center;
         gap: 1.5em;
@@ -48,9 +49,10 @@
     <a href = "/">//Profile</a>
     <a href = "/repos">//Repos</a>
     <a href = "/contact">//Contact</a>
+    <ThemeSwitcher />
 </nav>
 
 <div class="main-container fade">
-    <Toasts></Toasts>
+    <Toasts />
     <slot />
 </div>