feat: add auto-update script

[usarral]

This pull request introduces an auto-update.ps1 script to automate the update process for the Zed application on Windows. The script checks if Zed is running, fetches the latest version, downloads the new executable, and replaces the old version if it exists.

New auto-update script for Zed:

• Added a check to ensure the Zed application is not running before proceeding with the update. If Zed is running, the script exits with a message. (auto-update.ps1, auto-update.ps1R1-R39)
• Fetches the latest version number from a remote URL (latest_build.txt) and constructs the download URL for the corresponding release. (auto-update.ps1, auto-update.ps1R1-R39)
• Downloads the new executable to a temporary file, verifies the download, and removes the old executable if it exists. (auto-update.ps1, auto-update.ps1R1-R39)
• Renames the downloaded file to replace the old executable, completing the update process. (auto-update.ps1, auto-update.ps1R1-R39)