Tutorial for angular client generation with cobigen

[GuentherJulian]

Create a new tutorial that shows the generation of an angular app with cobigen.
https://devonfw.com/website/pages/docs/master-cobigen.asciidoc_how-to.html#howto_angular-client-generation.asciidoc

Possible steps:

• Install devonfw ide (you can use the restoreDevonfwIde command, since the installation process is not supposed to be part of this tutorial)
• Install cobigen cli
• Create a java project that contains a backend server or restore a project via restoreWorkspace command
• Build and run the project
• Create an angular project or use the devonfw application template (https://github.com/devonfw/devon4ng-application-template/)
• Run the angular project to show how it looks like
• Use cobigen to generate the angular source code out of the java files
• Maybe you have to change the user interface in the angular project to show the new components
• Show the newly created components