adds new features

[neomen]

This PR adds several new features to improve the project structure export functionality for LLM context:

New Features

1. --minify flag - Strips whitespace and empty lines from file contents to reduce token usage when exporting to single file for LLM context
2. Flag position flexibility - All flags can now be placed either before or after the directory argument (e.g., buildtree -s out.txt . -f "go,md" and buildtree -s out.txt -f "go,md" . both work)
3. Glob pattern support in filters - --filter now accepts glob patterns (e.g., *.go, config.*, *.md)
4. --ignore flag - Added support for ignoring specific files using glob patterns (e.g., *_test.go,*.log)
5. Default text file filtering - By default, only common text file extensions are exported (go, js, ts, py, md, json, yaml, xml, txt, etc.) to prevent binary files from being included