Add ADR Proposal for Documentation Versioning

Author: nigthknight

docs/adr/adr_0006.adoc

@@ -0,0 +1,43 @@
+[[ADR-0001]]
+= ADR-0001: How We Want to Handle Versions in Our Documentation
+
+[cols="h,d",grid=rows,frame=none,stripes=none,caption="Status",%autowidth]
+|====
+// Use one of the ADR status parameter based on status
+// Please add a cross reference link to the new ADR on 'superseded' ADR.
+// e.g.: {adr_suposed_by} <<ADR-0000>>
+| Status
+| PROPOSED
+
+| Date
+| 2020-10-12
+
+| Author(s)
+| Yannik Fuhrmeister <yannik.fuhrmeister@iteratec.com>
+// ...
+|====
+
+== Context
+
+We want to introduce versioning to be able to provide dokumentation for multiple versions of the SecureCodeBox.
+The tool that we are currently using for documentation is https://v2.docusaurus.io/[Docusaurus].
+Docusaurus provides the possibility to maintain multiple versions out of the box (https://v2.docusaurus.io/docs/versioning/[]).
+
+We will need to specify how many versions of the documentation we want to maintain to avoid inconsistencies and overhead.
+Furthermore, we need to decide which version increments need to have their own branch of documentation.
+
+== Decision
+
+* We introduce a new documentation version for every minor version (https://semver.org/[]) to ensure that the documentation is up to date
+* We maintain the latest 3 major versions (previous, current, next)
+* We maintain the latest minor version for each major version
+* We *do not* maintain patch versions nor multiple minor versions for each major version!
+* *Example:* For SecureCodeBox versions `1.9.9`, `2.3.2`, `2.3.3` and `3.0.0` the documentation versions would be `1.9.x`, `2.3.x` and `3.0.x`
+* *TL;DR* We maintain 3 versions of the documentation
+
+== Consequences
+
+* We need to update the documentation version everytime we increment minor or major versions of the SecureCodeBox (manually or with action)
+* Maintaining the documentation could be more difficult due to now increased number of documentation files
+* Documentation has to be maintained in two repositories because when creating a new version Docusaurus creates a copy of all files in this respository (see https://v2.docusaurus.io/docs/versioning/#directory-structure[])
+