docs: add DR for the new release process (eclipse-edc#206)

* docs: add DR for the new release process

* pr remarks

developer/decision-records/2024-08-26-new-release-process/README.md

@@ -0,0 +1,49 @@
+# New Release process
+
+## Decision
+
+The EDC release process needs to be improved to support bugfix releases.
+
+## Rationale
+
+Currently, the Release process starts from the main branch of every repository and it can be launched only for proper releases.
+For bugfix releases, some manual work needs to be done, that should be avoided.
+
+## Approach
+
+By "core repositories" we mean:
+- `Runtime-Metamodel`
+- `GradlePlugins`
+- `Connector`
+- `IdentityHub`
+- `FederatedCatalog`
+
+Release EDC components should follow a 2-phase process like it was done for [technology repos](../2024-08-13-technology-repos-release):
+- preparation
+- release
+
+### Preparation phase
+By "release preparation" we mean all the preparatory operations that are needed to permit a proper release.
+The workflow will take as input the desired version and the branch name to use as starting point.
+- a `release/x.y.z` or `bugfix/x.y.z` branch will be created on every core repository.
+- the project version, the upstream "edc" dependency and the DEPENDENCIES file will be bumped to `x.y.z-SNAPSHOT`
+- "trigger_snapshot" workflow will be called on every core repository following the dependency order
+
+For a bugfix release now it will be possible to backport/cherry-pick the commits needed
+
+### Release
+The release flow is the same for `release` and `bugfix` branches.
+It will take as an input the branch name from which the flow will be started.
+
+- all the "core repositories" are checked out on the selected branch
+- the "root" project is configured, with all the repos set as subprojects
+- the project version and the upstream "edc" dependency will be bumped to `x.y.z`
+- all the `DEPENDENCIES` files are updated to replace EDC `-SNAPSHOT` versions with proper versions
+- `DEPENDENCIES`, `LICENSE` and `NOTICE.md` files are included in the root project
+- the root project is built and published to maven central
+- a commit is done on every repo and pushed on remote
+- release workflow is called on every core repository, it will:
+  - push the version tag
+  - create the github release
+  - bump version on main if the version ended with `.0` (`release/`)
+  - publish autodoc if configured

developer/decision-records/README.md

@@ -27,6 +27,7 @@
 - [2024-05-27 EDC Maturity Levels and Deprecation Policy](2024-05-27-maturity-levels-deprecation-policy/)
 - [2024-07-17 Bootstrapping SQL Databases](2024-07-17-bootstrap-sql-database/)
 - [2024-08-13 Technology Repositories Release](2024-08-13-technology-repos-release/)
+- [2024-08-24 New Release process](./2024-08-26-new-release-process/)
 
 ## Repository-specific