feat: add GitHub icon and link to about page

- Introduced a new GitHub icon component and updated the icon mapping.
- Modified the IconSchema to include 'github'.
- Added a credit section in the about page linking to the GitHub repository.

Author: githyperplexed

src/lib/components/icons/github.svelte

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="w-5 h-5 fill-current" aria-hidden="true">
+	<path
+		d="M12 0c-6.626 0-12 5.373-12 12 0 5.302 3.438 9.8 8.207 11.387.599.111.793-.261.793-.577v-2.234c-3.338.726-4.033-1.416-4.033-1.416-.546-1.387-1.333-1.756-1.333-1.756-1.089-.745.083-.729.083-.729 1.205.084 1.839 1.237 1.839 1.237 1.07 1.834 2.807 1.304 3.492.997.107-.775.418-1.305.762-1.604-2.665-.305-5.467-1.334-5.467-5.931 0-1.311.469-2.381 1.236-3.221-.124-.303-.535-1.524.117-3.176 0 0 1.008-.322 3.301 1.23.957-.266 1.983-.399 3.003-.404 1.02.005 2.047.138 3.006.404 2.291-1.552 3.297-1.23 3.297-1.23.653 1.653.242 2.874.118 3.176.77.84 1.235 1.911 1.235 3.221 0 4.609-2.807 5.624-5.479 5.921.43.372.823 1.102.823 2.222v3.293c0 .319.192.694.801.576 4.765-1.589 8.199-6.086 8.199-11.386 0-6.627-5.373-12-12-12z"
+	/>
+</svg>

src/lib/components/icons/icon.svelte

@@ -2,6 +2,7 @@
 	import X from "$lib/components/icons/x.svelte";
 	import Youtube from "$lib/components/icons/youtube.svelte";
 	import Sheet from "$lib/components/icons/sheet.svelte";
+	import Github from "$lib/components/icons/github.svelte";
 
 	import type { IconType } from "$lib/types/icon";
 
@@ -14,7 +15,8 @@
 	const map = {
 		youtube: Youtube,
 		x: X,
-		sheet: Sheet
+		sheet: Sheet,
+		github: Github
 	};
 
 	const Component = $derived(map[name]);

src/lib/types/icon.ts

@@ -1,5 +1,5 @@
 import { z } from "zod";
 
-export const IconSchema = z.enum(["youtube", "x", "sheet"]);
+export const IconSchema = z.enum(["youtube", "x", "sheet", "github"]);
 
 export type IconType = z.infer<typeof IconSchema>;

src/routes/(content)/about/+page.svelte

@@ -80,6 +80,15 @@
 					@Hyperplexed
 				</Link>.
 			</Paragraph>
+
+			<div class="w-full max-w-sm pt-2">
+				<Credit
+					href="https://github.com/githyperplexed/extension-data-viewer"
+					label="extension-data-viewer"
+					description="Source Code"
+					icon="github"
+				/>
+			</div>
 		</Section>
 
 		<Section