* Initial support for ARMv8
* Add fallback mechanism
* Update changelog
* Update useragent
* Some typo and format changes
* Use `env:ProgramFiles(Arm)` to detect ARM64
- Move `default_architecture()` to `core.ps1`
* Rename 'ensure_architecture()' and 'default_architecture()'
* Refactor 'supports_architecture()' to 'Get-SupportedArchitecture()'
Co-authored-by: Hsiao-nan Cheung <niheaven@gmail.com>