Describe the schul-frei project on homepage

The three columns visible right now on the homepage talk about the advantages of using the schul-frei distribution, which is now called lanki.cloud. But lanki.cloud is not mentioned anywhere. This will cause confusion in the future when we start to promote lanki.cloud as a our software solution to connect our curated software.

My suggestion is to move everything software-related to a separate product-page (e.g. "solutions"-tab) and talk about the project and our goals on the homepage.