feat!: add credit configurations for banner image

BREAKING CHANGES: new mandatory fields added in `config.ts`

src/types/config.ts

@@ -14,6 +14,11 @@ export type SiteConfig = {
     enable: boolean
     src: string
     position?: string
+    credit: {
+      enable: boolean
+      text: string
+      url?: string
+    }
   }
 
   favicon: Favicon[]