Getting started from Spring Guides

[Eskibear]

There are lots of Spring Guides officially provided, good for developers to get started. See https://spring.io/guides

Corresponding repos are hosted on GitHub, and the repo names are following spring-guides/gs-*.

So a potential feature would be:

We can add a command like Spring Initializr: Getting Started from Guides, which lists all available guides with a short description. If users select an guide and a target folder, we clone the corresponding repository for them, and open corresponding guide page.