German Online Help for 8.5.0

Changes:
- OXUD-1108 Some minor updates & polishing
- OXUD-1109 Story OXUIB-1875 Global address book referenced in settings
- OXUD-1111 Remove some outdated content
- OXUD-1104 Update the descriptions for 'All settings' due to UI changes
- OXUD-1106 Story OXUIB-1854 gabFolderName not used in settings
- OXUD-1100 Remove 'Zoom-Integration einrichten' from the topic 'Zoom-Integration einrichten und konfigurieren'
- OXUD-1101 Various enhancements for index terms and glossary
- OXUD-1084 Check docu: Story OXUI-994 UI-Redesign: Notification area overhaul
- OXUD-1085 Check docu: OXUI-995 As a user I can configure a default signature for all my mail accounts
- OXUD-1086 Check docu: Story OXUI-986 As a user I can search in settings
- OXUD-1087 Check docu: Story OXUI-999 As a user the Settings App is shown as a modal dialog
- OXUD-1094 Fix outdated text in 'Save as distribution list' and 'Invite to new appointment'
- OXUD-1095 Fix the wrong image for detail view
- OXUD-1096 Update the Guard docu and other tiny polishing
- OXUD-1097 Story: Remove "My contact data" button from settings dialog