feat(workflow): Provides a common workflow

It runs all pipelines but prevents that a branch pipelines is started when there is an open merge request.

https://docs.gitlab.com/ee/ci/yaml/workflow.html#switch-between-branch-pipelines-and-merge-request-pipelines

documentation/chapters/templates/common/common-ci-workflow.adoc

@@ -0,0 +1,12 @@
+:gitlab-ci-file: common/common-ci-workflow.gitlab-ci.yml
+
+[[Common-Workflow]]
+== Common Workflow
+
+Within the `{gitlab-ci-file}` file we provide a common workflow.
+This workflow runs all pipelines (including branch pipelines, tag pipelines, merge request pipelines, triggerd pipelines, shedules-pipelines ...).
+However, it prevents that a branch pipeline starts, when there is an open merge request.
+To use our common workflow, just import the template.
+
+:template: {gitlab-ci-file}
+include::../../../template-printer.adoc[]

documentation/document.adoc

@@ -35,6 +35,7 @@ toc::[]
 
 include::generalInformation.adoc[leveloffset=1]
 include::chapters/templates/common/common-ci-variablen.adoc[leveloffset=1]
+include::chapters/templates/common/common-ci-workflow.adoc[leveloffset=1]
 
 == Contribution
 

templates/common/common-ci-workflow.gitlab-ci.yml

@@ -0,0 +1,6 @@
+workflow:
+  rules:
+    # Prevent branch pipelines when there is an open merge request
+    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS && $CI_PIPELINE_SOURCE == "push"
+      when: never
+    - when: always