Merge branch 'docs-add-servicenow-info' into 'master'

Docs: Add ServiceNow integration info

See merge request gitlab-org/gitlab!40007

doc/user/project/integrations/servicenow.md

+---
+stage: Create
+group: Ecosystem
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers
+---
+
+# ServiceNow integration
+
+ServiceNow offers several integrations to help centralize and automate your
+management of GitLab workflows.
+
+## GitLab spoke
+
+With the GitLab spoke in ServiceNow, you can automate actions for GitLab
+projects, groups, users, issues, merge requests, branches, and repositories.
+
+For a full list of features, see the
+[GitLab spoke documentation](https://docs.servicenow.com/bundle/orlando-servicenow-platform/page/administer/integrationhub-store-spokes/concept/gitlab-spoke.html).
+
+You must [configure GitLab as an OAuth2 authentication service provider](../../../integration/oauth_provider.md),
+which involves creating an application and then providing the Application ID
+and Secret in ServiceNow.
+
+## GitLab SCM and Continuous Integration for DevOps
+
+In ServiceNow DevOps, you can integrate with GitLab repositories and GitLab CI/CD
+to centralize your view of GitLab activity and your change management processes.
+You can:
+
+- Track information about activity in GitLab repositories and CI/CD pipelines in
+  ServiceNow.
+- Integrate with GitLab CI/CD pipelines, by automating the creation of change
+  tickets and determining criteria for changes to auto-approve.
+
+For more information, refer to the following ServiceNow resources:
+
+- [ServiceNow DevOps home page](https://www.servicenow.com/products/devops.html)
+- [Install DevOps](https://docs.servicenow.com/bundle/paris-devops/page/product/enterprise-dev-ops/task/activate-dev-ops.html)
+- [Install DevOps Integrations](https://docs.servicenow.com/bundle/paris-devops/page/product/enterprise-dev-ops/task/activate-dev-ops-integrations.html)
+- [GitLab SCM and Continuous Integration for DevOps](https://store.servicenow.com/sn_appstore_store.do#!/store/application/54dc4eacdbc2dcd02805320b7c96191e/)
+- [Model a GitLab CI pipeline in DevOps](https://docs.servicenow.com/bundle/paris-devops/page/product/enterprise-dev-ops/task/model-gitlab-pipeline-dev-ops.html).