Performance improvements with Swift 6.2 features

[3a4oT]

Summary

This PR implements performance optimizations using Swift 6.2 features:

• Added consuming parameter ownership to parsing functions for reduced memory overhead
• Fixed incorrect attribute access syntax in README documentation
• Optimized CSS parser to use Array with reserveCapacity instead of String concatenation
• Added consuming parameters to internal CSS translator functions

Changes

• MemoryParser.parse(string:) now uses consuming parameter
• parseXML/parseHTML functions use consuming parameter
• ParsingService methods use consuming parameter
• CSS parser refactored to avoid repeated String allocations
• All changes validated with existing test suite (18/18 tests passing)