Merge branch 'steps-init-definition' into 'master'

Initial steps definition added to blueprint glossary

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/117196



Merged-by: Marcel Amirault <mamirault@gitlab.com>
Approved-by: Grzegorz Bizon <grzegorz@gitlab.com>
Approved-by: Marcel Amirault <mamirault@gitlab.com>
Co-authored-by: Mark Nuzzo <mnuzzo@gitlab.com>

doc/architecture/blueprints/ci_pipeline_components/index.md

@@ -100,6 +100,7 @@ identifying abstract concepts and are subject to changes as we refine the design
 - **Catalog resource** is the single item displayed in the catalog. A components repository is a catalog resource.
 - **Version** is a specific revision of catalog resource. It maps to the released tag in the project,
   which allows components to be pinned to a specific revision.
+- **Steps** is a collection of instructions for how jobs can be executed.
 
 ## Definition of pipeline component