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/check_list/comments.html

@@ -0,0 +1,32 @@
+
+<!-- foo-->
+<ul>
+  <!-- bar-->
+  <li>one</li>
+  <!-- baz-->
+  <li>two</li>
+</ul>
+<!--
+ul
+  li foo
+
+-->
+<!-- block
+// inline follow
+li three
+
+-->
+<!-- block
+// inline followed by tags
+ul
+  li four
+
+-->
+<!--if IE lt 9
+// inline
+script(src='/lame.js')
+// end-inline
+
+-->
+<p>five</p>
+<div class="foo">// not a comment</div>