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/text.html

@@ -0,0 +1,36 @@
+
+<option value="">-- (selected) --</option>
+<p></p>
+<p></p>
+<p>
+  foo
+  bar
+  
+  
+  baz
+</p>
+<p>
+  foo
+  
+  
+  bar
+  baz
+  
+</p>foo
+
+
+bar
+baz
+
+<pre>foo
+  bar
+    baz
+.</pre>
+<pre>foo
+  bar
+    baz
+.
+</pre>foo
+  bar
+    baz
+.