feat(adr): Add ADR-0006 for Branching Strategy

adr/ADR-0006-branching-strategy.md

@@ -0,0 +1,60 @@
+---
+num: 6 # allocate an id when the draft is created
+title: Branching Strategy
+status: "Draft" # One of Draft, Accepted, Rejected
+authors:
+  - "ruivieira" # One item for each author, as github id or "firstname lastname"
+tags:
+  - "community" # e.g. service, python, java, etc
+---
+
+## Title
+
+Branching Strategy
+
+## Context and Problem Statement
+
+Currently, we maintain a dedicated `release-x` branch for each community release, so that community users can receive releases periodically. However, our downstream consumers rely on the `main` branch for ongoing development and require specific updates. However, this might include commits in `main` which are not yet fully ready either for community releases or downstream.
+
+
+## Goals
+
+To enables us to provide downstream consumers with updates/fixes in stable branch, without disrupting the upstream development/release cycle on `main`.
+
+## Non-goals
+
+N/A
+
+## Current situation
+
+See [Context](#context-and-problem-statement).
+
+
+## Proposal
+
+I propose creating an `release-x-post1` branch that:
+1. Builds on the most recent community release (`release-x`) by incorporating selected changes and fixes that downstream consumers need.
+2. Remains stable for downstream use, while allowing `main` development to continue at a normal pace.
+3. Close the gap between major community releases, by allowing downstream consumers to get fixes and updates without having to wait for community official `release-(x+1)` releases.
+
+![branching system](assets/adr-0006-branching-system.png)
+
+## Threat model
+
+N/A
+
+## Alternatives Considered / Rejected
+
+N/A
+
+## Challenges
+
+Automation must be put in place to create `x-post1` branches simultaneously to `x`.
+
+## Dependencies
+
+N/A
+
+## Consequences if not completed
+
+Downstream consumers might get unwanted commits from `main`.

adr/README.md

@@ -18,4 +18,5 @@
 # Approved ADRs
 
 * [ADR-0001: TrustyAI external library integration](ADR-0001-trustyai-external-library-integration.md)
-* [ADR-0002: Metrics and XAI namespaces](ADR-0002-metrics-and-xai-namespaces.md)
+* [ADR-0002: Metrics and XAI namespaces](ADR-0002-metrics-and-xai-namespaces.md)
+* [ADR-0006: Branching Strategy](ADR-0006-branching-strategy.md)