provide a better introduction to new Zig users

[Techatrix]

Consider the following steps that a new user might take to get started with Zig:

1. Open VS Code.
2. Open a new, empty folder as a workspace (optional).
3. Install the Zig VS Code extension.

At this point, the user might expect some guidance, perhaps a welcome message with next steps, a confirmation that Zig has been installed, or a suggestion to run zig init. However, what actually happens is... nothing.

A potential solution is to use VS Code's Walkthroughs feature. This could provide a structured introduction, guiding users through some setup steps to help them get starting with learning Zig. Here is an example of what could be included:

1. create a new Zig project with zig init
2. enable ZLS (optional)
3. compile and run the project (should integrate with build system VS Code debugging API in the future)
4. run tests (should integrate with build system and VS Code testing API in the future future)
5. checkout https://ziglang.org/learn/ and https://github.com/ziglang/zig/wiki/Community

For inspiration, the vscode-python extension and VS Code itself offer well-designed walkthroughs that could serve as a useful reference.

As an alternative solution, It might just be enough to display a message with a button that will create a new Zig project with zig init.

[Vexu]

The Walkthrough feature seems nice, do we know how people generally feel about it? I'm sure it'll be better received than the popups we did previously.

[basdp]

Flutter does this in a really nice way.
See this documentation for a quick overview of what this flow looks like for Flutter in VS Code:
https://docs.flutter.dev/get-started/quick