docs: update documentation structure and examples for Arrays & Strings guide

docs/content/01-coding/01-arrays-and-strings/03-reverse-string.mdx

@@ -0,0 +1,4 @@
+---
+sidebar:
+  icon: circle-question-mark
+---

docs/content/01-coding/01-arrays-and-strings/meta.ts

@@ -1,5 +1,6 @@
 import { defineMeta } from "blume";
 
 export default defineMeta({
+  title: "Arrays & Strings",
   order: 4,
 });