Support additional languages beyond French

[jwalsh]

Currently, the syntax tree streamer is optimized for French text (Proust). Add support for additional languages to make the tool more versatile.

Required features:

• Add language detection or explicit language setting
• Support for loading appropriate spaCy language models
• Language-specific tokenization and parsing rules
• Handling of language-specific grammar features
• Support for right-to-left languages if possible

Implementation steps:

1. Abstract language-specific logic in the parser
2. Create pluggable language handlers
3. Add language configuration options
4. Update documentation with supported languages
5. Add examples in multiple languages

This enhancement would make the syntax tree streamer useful for a wider range of linguistic analysis tasks and text processing applications.