Add new scripts for managing copyright headers and publishing releases

- Created `add_headers.ps1` to automate the addition of copyright headers to C# and AXAML files.
- Introduced `publish_release_standalone.ps1` for streamlined release publishing with comprehensive logging and error handling.
- Added `update_old_builds.ps1` to merge TOML files with corresponding markdown files, ensuring up-to-date documentation and valid TOML structures.

Author: th3w1zard1