feat(dev): add support for footer override

adds support for overriding the footer component, similar to the TopBar override setup. Users can now customize footer content such as legal terms, contact info, and copyrights.

this change introduces `Footer.astro` and `FooterWrapper.astro` files to allow flexible slotting of footer items, improving customization for standalone tutorial deployments

close #323

Author: RonithManikonda

Diff for: packages/astro/src/default/components/Footer.astro

@@ -0,0 +1,13 @@
+<nav
+  class="bg-tk-elements-footer-backgroundColor border-t border-tk-elements-app-borderColor flex justify-between p-4"
+>
+  <div class="flex-1">
+    <slot name="terms" />
+  </div>
+  <div class="flex-1">
+    <slot name="contact-info" />
+  </div>
+  <div class="flex-1">
+    <slot name="copyright" />
+  </div>
+</nav>

Diff for: packages/astro/src/default/components/FooterWrapper.astro

@@ -0,0 +1,14 @@
+---
+// FooterWrapper.astro
+import { Footer } from 'tutorialkit:override-components';
+import Terms from './Terms.astro';
+import ContactInfo from './ContactInfo.astro';
+
+const currentYear = new Date().getFullYear();
+---
+
+<Footer>
+  <Terms slot="terms" />
+  <ContactInfo slot="contact-info" />
+  <p slot="copyright">© {currentYear} Your Company. All rights reserved.</p>
+</Footer>