feat: multiple category feature

src/routes/+layout.svelte

@@ -8,7 +8,7 @@
   // Get categories:
   import { svgs } from '@/data/svgs';
   const categories = svgs
-    .map((svg) => svg.category)
+    .flatMap((svg) => Array.isArray(svg.category) ? svg.category : [svg.category])
     .filter((category, index, array) => array.indexOf(category) === index);
 
   // Icons:

src/routes/directory/[slug]/+page.ts

@@ -13,7 +13,13 @@ export const load = (async ({ params }) => {
   }
 
   // Filter out the svg with the matching slug:
-  const svgsByCategory = svgs.filter((svg: iSVG) => svg.category.toLowerCase() === slug);
+  const svgsByCategory = svgs.filter((svg: iSVG) => {
+    if (Array.isArray(svg.category)) {
+      return svg.category.some(categoryItem => categoryItem.toLowerCase() === slug);
+    } else {
+      return svg.category.toLowerCase() === slug;
+    }
+  });
 
   return {
     category: slug as string,