Improvement: Process descriptions

[PandaeDo]

Summary of improvement findings at persistency process pilot from @kroehnd and @PandaeDo

• Main page of https://eclipse-score.github.io/score/main/features/index.html shall have a description for a better orientation. Overview diagrams like the platform architecture might be helpful
• Similar to that the first page of the feature https://eclipse-score.github.io/score/main/features/persistency/index.html shall contain a description. It could be separated from the index https://eclipse-score.github.io/score/main/features/persistency/kvs/index.html
• The content in the feature request "how to teach this" might be better separated so it's easier to find
• When we keep the chapter than it might be useful to link it in the module description
• A glossary might be helpful. It should also be possible to get guidance that used definitions are consistent
• AoU docs-as-code template is not that one that's described in the process description
• Architecture checklist (https://eclipse-score.github.io/process_description/main/process_areas/architecture_design/guidance/architecture_inspection_checklist.html) in general concepts is mixed for feature and component. It might be helpful it it's a little bit separated --> Discussion with example ARC_02_01 is the meaning of the questions to use them for both levels with different scope.
• In general we have the experience in the pilot and also when we double-check it with the other features that some information's are there because the process require its. It could be helpful to optimize the required thinks to a minimum and mark the rest as optional