Add tier badges to CI doc files

Adds tier badges to several CI documentation pages.

doc/ci/migration/circleci.md

@@ -6,7 +6,7 @@ comments: false
 type: index, howto
 ---
 
-# Migrating from CircleCI
+# Migrating from CircleCI **(FREE)**
 
 If you are currently using CircleCI, you can migrate your CI/CD pipelines to [GitLab CI/CD](../introduction/index.md),
 and start making use of all its powerful features. Check out our

doc/ci/migration/jenkins.md

@@ -6,7 +6,7 @@ comments: false
 type: index, howto
 ---
 
-# Migrating from Jenkins
+# Migrating from Jenkins **(FREE)**
 
 A lot of GitLab users have successfully migrated to GitLab CI/CD from Jenkins. To make this
 easier if you're just getting started, we've collected several resources here that you might find useful

doc/ci/pipelines/job_artifacts.md

@@ -6,7 +6,7 @@ disqus_identifier: 'https://docs.gitlab.com/ee/user/project/pipelines/job_artifa
 type: reference, howto
 ---
 
-# Job artifacts
+# Job artifacts **(FREE)**
 
 > Introduced in [GitLab 12.4](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/16675), artifacts in internal and private projects can be previewed when [GitLab Pages access control](../../administration/pages/index.md#access-control) is enabled.
 

doc/ci/pipelines/pipeline_architectures.md

@@ -5,7 +5,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 type: reference
 ---
 
-# Pipeline Architecture
+# Pipeline architecture **(FREE)**
 
 Pipelines are the fundamental building blocks for CI/CD in GitLab. This page documents
 some of the important concepts related to them.

doc/ci/pipelines/pipeline_artifacts.md

@@ -5,7 +5,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 type: reference, howto
 ---
 
-# Pipeline artifacts
+# Pipeline artifacts **(FREE)**
 
 Pipeline artifacts are files created by GitLab after a pipeline finishes. These are different than [job artifacts](job_artifacts.md) because they are not explicitly managed by the `.gitlab-ci.yml` definitions.
 

doc/ci/pipelines/pipeline_efficiency.md

@@ -5,7 +5,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 type: reference
 ---
 
-# Pipeline Efficiency
+# Pipeline efficiency **(FREE)**
 
 [CI/CD Pipelines](index.md) are the fundamental building blocks for [GitLab CI/CD](../README.md).
 Making pipelines more efficient helps you save developer time, which: