Add devcontainer

[sjev]

This pull request introduces a development container setup for the project, including a Dockerfile and configuration file, and updates a script to improve compatibility. The changes aim to streamline the development environment by providing a pre-configured container and addressing minor script improvements.

Development container setup:

• .devcontainer/Dockerfile: Added a Dockerfile that sets up a development container with Go, Node.js, and pnpm pre-installed. It also creates a non-root user, configures pnpm to avoid long path issues, and sets up the working directory.
• .devcontainer/devcontainer.json: Added a configuration file for the development container, specifying the Dockerfile, build arguments, port forwarding, and recommended VS Code extensions for Go, Git, and ESLint.

Script improvement:

• scripts/build.sh: Changed the shell interpreter from sh to bash to improve compatibility and ensure the script exits when any command fails.

[Cadavanaugh]

This is actually a pretty good contribution.

[sjev]

@boojack I don't mind that you rejected this PR, but could you provide a reason why?

I realized myself that VS Code devcontainer is maybe not an optimal way to facilitate development.
Instead, I already switched to a development docker stack that runs backend with mock database and a frontend server running in separate containers.
Would that be acceptible as a PR?