Updated docs

docs/contact.md

docs/customization.md

docs/get-started.md

docs/images/architecture.png

docs/images/auth-ssl.png

docs/images/custom_icon.png

docs/images/custom_logo.png

docs/images/deployment-tuwien.png

docs/images/groups-roles.png

docs/system.md

misc/architecture.drawio

misc/diagrams.drawio

swagger/api-container.yaml

swagger/api-database.yaml

swagger/api-identifier.yaml

swagger/api-metadata.yaml

swagger/api-query.yaml

swagger/api-semantics.yaml

swagger/api-table.yaml

swagger/api-user.yaml