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/attrs.html

@@ -0,0 +1,20 @@
+<a href="/contact">contact</a><a class="button" href="/save">save</a><a foo="foo" bar="bar" baz="baz"></a><a foo="foo, bar, baz" bar="1"></a><a foo="((foo))" bar="1"></a>
+<select>
+  <option value="foo" selected="selected">Foo</option>
+  <option selected="selected" value="bar">Bar</option>
+</select><a foo="class:"></a>
+<input pattern="\S+"/><a href="/contact">contact</a><a class="button" href="/save">save</a><a foo="foo" bar="bar" baz="baz"></a><a foo="foo, bar, baz" bar="1"></a><a foo="((foo))" bar="1"></a>
+<select>
+  <option value="foo" selected="selected">Foo</option>
+  <option selected="selected" value="bar">Bar</option>
+</select><a foo="class:"></a>
+<input pattern="\S+"/>
+<foo terse="true"></foo>
+<foo date="1970-01-01T00:00:00.000Z"></foo>
+<foo abc="abc" def="def"></foo>
+<foo abc="abc" def="def"></foo>
+<foo abc="abc" def="def"></foo>
+<foo abc="abc" def="def"></foo>
+<foo abc="abc" def="def"></foo>
+<foo abc="abc" def="def"></foo>
+<div foo="bar" bar="<baz>"></div><a foo="foo" bar="bar"></a><a foo="foo" bar="bar"></a>