feat: add include demo page to showcase include directive

- Add includes/some_partial.pug partial in demo views
- Add pages/include-demo.pug page using include directive
- Add /include-demo route in demo server
- Add link to include demo in about page
- Fix test_includes.zig path in build.zig
- Add test_views for include testing

src/examples/demo/build.zig.zon

@@ -5,7 +5,7 @@
     .minimum_zig_version = "0.15.2",
     .dependencies = .{
         .pugz = .{
-            .path = "../..",
+            .path = "../../..",
         },
         .httpz = .{
             .url = "git+https://github.com/karlseguin/http.zig?ref=master#9ef2ffe8d611ff2e1081e5cf39cb4632c145c5b9",

src/examples/demo/src/main.zig

@@ -301,6 +301,18 @@ fn about(app: *App, _: *httpz.Request, res: *httpz.Response) !void {
     res.body = html;
 }
 
+fn includeDemo(app: *App, _: *httpz.Request, res: *httpz.Response) !void {
+    const html = app.view.render(res.arena, "pages/include-demo", .{
+        .title = "Include Demo",
+        .cartCount = "2",
+    }) catch |err| {
+        return renderError(res, err);
+    };
+
+    res.content_type = .HTML;
+    res.body = html;
+}
+
 fn notFound(app: *App, _: *httpz.Request, res: *httpz.Response) !void {
     res.status = 404;
 
@@ -389,6 +401,7 @@ pub fn main() !void {
     router.get("/products/:id", productDetail, .{});
     router.get("/cart", cart, .{});
     router.get("/about", about, .{});
+    router.get("/include-demo", includeDemo, .{});
 
     // Static files
     router.get("/css/*", serveStatic, .{});
@@ -410,6 +423,7 @@ pub fn main() !void {
         \\   GET /products/:id  - Product detail
         \\   GET /cart          - Shopping cart
         \\   GET /about         - About page
+        \\   GET /include-demo  - Include directive demo
         \\
         \\ Press Ctrl+C to stop.
         \\

src/examples/demo/views/includes/some_partial.pug

@@ -0,0 +1,4 @@
+.info-box
+  h3 Included Partial
+  p This content comes from includes/some_partial.pug
+  p It demonstrates the include directive for reusable template fragments.

src/examples/demo/views/pages/about.pug

@@ -47,5 +47,7 @@ block content
                 a(href="https://github.com/ankitpatial/pugz") GitHub Repository
               li
                 a(href="/products") View Products
+              li
+                a(href="/include-demo") Include Demo
               li
                 a(href="/") Back to Home

src/examples/demo/views/pages/include-demo.pug

@@ -0,0 +1,20 @@
+extends layouts/base.pug
+
+block title
+  title Include Demo | Pugz Store
+
+block content
+  section.page-header
+    .container
+      h1 Include Demo
+      p Demonstrating the include directive
+
+  section.section
+    .container
+      h2 Content from this page
+      p The box below is included from a separate partial file.
+
+      include includes/some_partial.pug
+
+      h2 After the include
+      p This content comes after the included partial.