docs: add first skeleton for pages

docs/api/core/filter.md

+# Filter
+
+!!! todo
+    write usage api docs

docs/api/core/logging.md

+# Logging
+
+!!! todo
+    write usage api docs

docs/api/core/registered-systems.md

+# Registered Systems
+
+!!! todo
+    write usage api docs

docs/api/core/ticket-assignee.md

+# Ticket Assignee
+
+!!! todo
+    write usage api docs

docs/api/core/ticket-builder.md

+# Ticket-Builder
+
+!!! todo
+    write usage api docs

docs/api/core/ticket-system-builder.md

+# Ticketsystem-Builder
+
+!!! todo
+    write usage api docs

docs/api/core/ticket-system.md

+# Ticketsystem
+
+!!! todo
+    write usage api docs

docs/api/core/ticket.md

+# Ticket
+
+!!! todo
+    write usage api docs

docs/api/exceptions.md

+# Exceptions
+
+!!! todo
+    - list exceptions available
+    - explain inheritance structure

docs/api/index.md

+# Java-API
+
+!!! todo
+    - introductional text about library usage
+    - api docs structure explanation
+    - hint about no autogenerated JavaDoc, but manually written docs

docs/api/systems/gitlab/filter.md

+# Gitlab-Filter
+
+!!! todo
+    write usage api docs

docs/api/systems/gitlab/ticket-assignee.md

+# Gitlab-Ticket Assignee
+
+!!! todo
+    write usage api docs

docs/api/systems/gitlab/ticket-builder.md

+# Gitlab-Ticket-Builder
+
+!!! todo
+    write usage api docs

docs/api/systems/gitlab/ticket-system-builder.md

+# Gitlab-Ticketsystem-Builder
+
+!!! todo
+    write usage api docs

docs/api/systems/gitlab/ticket-system.md

+# Gitlab-Ticketsystem
+
+!!! todo
+    write usage api docs

docs/api/systems/gitlab/ticket.md

+# Gitlab-Ticket
+
+!!! todo
+    write usage api docs

docs/index.md

+[![pipeline state](https://transfer.hft-stuttgart.de/gitlab/9Lukas5/unified-ticketing/badges/master/pipeline.svg)](https://transfer.hft-stuttgart.de/gitlab/9Lukas5/unified-ticketing/pipelines)
+[![License GPLv3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)
+[![Conventional Commits](https://img.shields.io/badge/Conventional%20Commits-1.0.0-yellow.svg)](https://conventionalcommits.org)
+
 # Unified Ticketing
 
 !!! Todo
+    - generally what this is about
+    - who's responsible for it

docs/unified-ticketing/changelog-softlink.md

+../../CHANGELOG.md
\ No newline at end of file

docs/unified-ticketing/contributing.md

+# Contributing
+
+!!! todo
+    - Write Basic stuff a contributor needs to full-fill & know
+    - link to the Developers Guide found in top-bar

docs/unified-ticketing/license-softlink.md

+../../LICENSE.md
\ No newline at end of file