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/sample_data/pug/test/cases/attrs-data.html

@@ -0,0 +1,6 @@
+<foo data-user="{&quot;name&quot;:&quot;tobi&quot;}"></foo>
+<foo data-items="[1,2,3]"></foo>
+<foo data-username="tobi"></foo>
+<foo data-escaped="{&quot;message&quot;:&quot;Let's rock!&quot;}"></foo>
+<foo data-ampersand="{&quot;message&quot;:&quot;a quote: &amp;quot; this &amp; that&quot;}"></foo>
+<foo data-epoc="1970-01-01T00:00:00.000Z"></foo>