fix: add scoped error logging for lexer/parser errors

- Add std.log.scoped(.pugz) to template.zig and view_engine.zig
- Log detailed error info (code, line, column, message) when parsing fails
- Log template path context in ViewEngine on parse errors
- Remove debug print from lexer, use proper scoped logging instead
- Move benchmarks, docs, examples, playground, tests out of src/ to project root
- Update build.zig and documentation paths accordingly
- Bump version to 0.3.1

tests/test_includes.zig

@@ -0,0 +1,35 @@
+const std = @import("std");
+const pugz = @import("pugz");
+
+pub fn main() !void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
+    // Test: Simple include from test_views
+    var engine = pugz.ViewEngine.init(allocator, .{
+        .views_dir = "test_views",
+    }) catch |err| {
+        std.debug.print("Init Error: {}\n", .{err});
+        return err;
+    };
+    defer engine.deinit();
+
+    const html = engine.render(allocator, "home", .{}) catch |err| {
+        std.debug.print("Error: {}\n", .{err});
+        return err;
+    };
+    defer allocator.free(html);
+
+    std.debug.print("=== Rendered HTML ===\n{s}\n=== End ===\n", .{html});
+
+    // Verify output contains included content
+    if (std.mem.indexOf(u8, html, "Included Partial") != null and
+        std.mem.indexOf(u8, html, "info-box") != null)
+    {
+        std.debug.print("\nSUCCESS: Include directive works correctly!\n", .{});
+    } else {
+        std.debug.print("\nFAILURE: Include content not found!\n", .{});
+        return error.TestFailed;
+    }
+}