Clarify categories / categorization and their goals

[MarkusTiede]

e.g. business: what's the purpose

• the upstream project used in business context
• the concrete downstream project with customer context

categories - what's in focus

• downstream business cases
• upstream open projects

side note: don't mix these within one category

dimension

• person
• data

[MarkusTiede]

Resolving for now - thanks @mirodietiker for this input. Please feel free to reopen any time: not reflecting for this years application process.