docs: add code review guide (#2772)

CODE_REVIEW.md

@@ -0,0 +1,73 @@
+# Code review requiements
+
+This document describe responsibilities of code reviewers when reviewing PRs.
+
+Pull request process is described in [contributing guide](./CONTRIBUTING.md#submitting-pull-requests)
+
+## Base checklist
+
+- All automated test steps pass (e.g. tests, lints, build)
+- PR title follows [commit conventions](CONTRIBUTING.md#commit-conventions)
+    - If PR format is different, reviewer should change it to follow the conventions
+- PR has a description with reasoning and change overview
+    - If description is missing but clear for reviewer, reviewer may add a comment or edit description
+- New feature or fix has tests proving it works
+    - Reviewer should request changes from contributor to add tests
+- If PR changes documented behaviour, there should be update to `/docs` or inline comments
+    - Reviewer should request changes from contributor to update docs
+- If PR introduces breaking changes, fixes a bug or adds a new feature, there should be a [release note](#release-notes)
+    - Reviewer may request changes from the contributor to add a release note
+    - Reviewer may add a release note by themself in order to unblock the merge process
+
+## Requesting changes
+
+It's recommended to request changes by submitting `comment` type reviews.
+`Request changes` type review would block merging until requester approves the
+changes, this can slow down the process if there are multiple reviewers.
+
+## Approving and merging
+
+We use `kueue` bot to merge approved PRs.
+
+If PR is approved, all checks are passing and it has the `kueue` label, it will
+be automatically squashed and merged.
+
+For PRs from Kanister developers, the committer should add the `kueue` label after
+PR was approved.
+
+For PRs from community, the reviewer should add the `kueue` label.
+
+## Release notes
+
+Kanister is using the [reno](https://docs.openstack.org/reno/latest/) tool to generate changelogs from release note files.
+
+To add release note one could run:
+
+```
+make reno-new note=<note_name>
+```
+
+Note name should be a short description of a change.
+
+File format is described in [reno docs](https://docs.openstack.org/reno/latest/user/usage.html#editing-a-release-note)
+
+Typical examples would be:
+
+```
+---
+features:
+  - Added new functionality doing X
+```
+
+Or:
+
+```
+---
+fixes:
+  - Fixed bug with pod output format
+upgrade:
+  - Make sure custom blueprints follow pod output format spec
+```
+
+See [release notes](./releasenotes/README.md) for more info.
+

CONTRIBUTING.md

@@ -95,6 +95,16 @@ We are using squash and merge approach to PRs which means that commit descriptio
 
 It's recommended to use conventional commits when strarting a PR, but follow-up commits in the PR don't have to follow the convention.
 
+### Release notes
+
+If submitted change fixes a bug, introduces a new feature or breaking change, contributor should add a release note.
+Kanister is using the [reno](https://docs.openstack.org/reno/latest/) tool to track release notes.
+
+Release note can be added with `make reno-new note=<note_name>` command, which will create a note file.
+Contributor should edit and commit the note file.
+
+See [release notes](./releasenotes/README.md) for more info.
+
 ### Submitting Pull Requests
 
 **PR titles should be in following format:**