The default value for the NPM package to update was changed from
`@github/copilot` to `@zed-industries/claude-code-acp`. This aligns the
script with the current package being maintained or targeted by the
update process.
* Introduced `PKGBUILD` to define packaging information for the Claude Code
extension.
* Added `.gitignore` to exclude build artifacts and temporary files.
* Created `updpkg.sh` to automate checking for and updating the package version
in `PKGBUILD`.
Signed-off-by: Chmouel Boudjnah <chmouel@chmouel.com>
