feat: add bun installation features via GitHub releases and asdf version manager

[mthsmb]

This pull request introduces two new features for installing Bun, a fast all-in-one JavaScript runtime, in devcontainers:

1. Bun Installation via GitHub Releases

• Installs Bun using the official GitHub releases.
• Ensures the latest or a specific version of Bun is installed based on the platform requirements of the user's system.
• Supports Linux (x86_64 and aarch64), macOS (x86_64 and arm64).

2. Bun Installation via asdf Version Manager

• Installs Bun using the asdf version manager and the asdf-bun plugin.
• Allows specifying and switching between different versions of Bun easily.
• Leverages the asdf-bun plugin, which is already included in the official asdf plugins repository.

Both features provide a convenient and flexible way to incorporate Bun into your devcontainer setup. They allow you to choose between a direct installation via GitHub releases or a version-managed installation using asdf.

Example usage in a devcontainer configuration:

"features": {
 "ghcr.io/devcontainers-contrib/features/bun:1": {},
 "ghcr.io/devcontainers-contrib/features/bun-asdf:1": {}
}

[evilhamsterman]

This project is not associated with the devcontainer project and appears to have been abandoned #628 . The official project has removed all devcontainer-contrib features from their listing. devcontainers/devcontainers.github.io#451. There is a fork that is being worked on to update and maintain the features https://github.com/devcontainers-extra/features