[DOCS] Add maintainer information to README.md

README.md

@@ -128,3 +128,61 @@ and `Resources/Private/Backend/Partials/Translation/DefaultTranslationDropdown.h
 > Modifed backend templates are listed here describing the modification, for
 > example, if one or more [InjectVariableViewhelper](#injectvariablesviewhelper)
 > has been placed along with the identifier and use-case.
+
+## Create a release (maintainers only)
+
+Prerequisites:
+
+* git binary
+* ssh key allowed to push new branches to the repository
+* GitHub command line tool `gh` installed and configured with user having permission to create pull requests.
+
+**Prepare release locally**
+
+> Set `RELEASE_BRANCH` to branch release should happen, for example: 'main'.
+> Set `RELEASE_VERSION` to release version working on, for example: '1.0.0'.
+
+```shell
+echo '>> Prepare release pull-request' ; \
+  RELEASE_BRANCH='main' ; \
+  RELEASE_VERSION='1.0.0' ; \
+  git checkout main && \
+  git fetch --all && \
+  git pull --rebase && \
+  git checkout ${RELEASE_BRANCH} && \
+  git pull --rebase && \
+  git checkout -b prepare-release-${RELEASE_VERSION} && \
+  composer require --dev "typo3/tailor" && \
+  ./.Build/bin/tailor set-version ${RELEASE_VERSION} && \
+  composer remove --dev "typo3/tailor" && \
+  git add . && \
+  git commit -m "[TASK] Prepare release ${RELEASE_VERSION}" && \
+  git push --set-upstream origin prepare-release-${RELEASE_VERSION} && \
+  gh pr create --fill-verbose --base ${RELEASE_BRANCH} --title "[TASK] Prepare release for ${RELEASE_VERSION} on ${RELEASE_BRANCH}" && \
+  git checkout main && \
+  git branch -D prepare-release-${RELEASE_VERSION}
+```
+
+Check pull-request and the pipeline run.
+
+**Merge approved pull-request and push version tag**
+
+> Set `RELEASE_PR_NUMBER` with the pull-request number of the preparation pull-request.
+> Set `RELEASE_BRANCH` to branch release should happen, for example: 'main' (same as in previous step).
+> Set `RELEASE_VERSION` to release version working on, for example: `0.1.4` (same as in previous step).
+
+```shell
+RELEASE_BRANCH='main' ; \
+RELEASE_VERSION='1.0.0' ; \
+RELEASE_PR_NUMBER='123' ; \
+  git checkout main && \
+  git fetch --all && \
+  git pull --rebase && \
+  gh pr checkout ${RELEASE_PR_NUMBER} && \
+  gh pr merge -rd ${RELEASE_PR_NUMBER} && \
+  git tag ${RELEASE_VERSION} && \
+  git push --tags
+```
+
+This triggers the `on push tags` workflow (`publish.yml`) which creates the upload package,
+creates the GitHub release and also uploads the release to the TYPO3 Extension Repository.