Add announcement date to release post body

data/deprecations/14-3-database-deprecate-legacy-database-conf.yml

 - name: "Legacy database configuration"
   announcement_milestone: "14.3"
+  announcement_date: "2021-09-22"
   removal_milestone: "15.0"
   body: |
    The syntax of [GitLabs database](https://docs.gitlab.com/omnibus/settings/database.html)

data/deprecations/14-3-repository-push-audit-events.yml

@@ -11,4 +11,4 @@
   tiers: Premium
   issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/337993
   documentation_url: https://docs.gitlab.com/ee/administration/audit_events.html#repository-push
-  announcement_date: 2021-09-02 # https://gitlab.com/gitlab-org/gitlab/-/merge_requests/69024
+  announcement_date: "2021-09-02" # https://gitlab.com/gitlab-org/gitlab/-/merge_requests/69024

data/deprecations/deprecation_omniauth-kerberos_gem.yml

@@ -11,5 +11,5 @@
   tiers: [Premium, Ultimate]
   issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/337384
   documentation_url: https://docs.gitlab.com/ee/integration/kerberos.html#upgrading-from-password-based-to-ticket-based-kerberos-sign-ins
-  announcement_date: 2021-22-09
+  announcement_date: "2021-09-22"
 

data/deprecations/distribution_deprecations_14-3.yml

 - name: "Rename Task Runner pod to Toolbox" # The name of the feature to be deprecated
   announcement_milestone: "14.2" # The milestone when this feature was first announced as deprecated.
+  announcement_date: "2021-09-22"
   removal_milestone: "14.4" # the milestone when this feature is planned to be removed
   body: | # Do not modify this line, instead modify the lines below.
     The Task Runner pod is used to execute periodic housekeeping tasks within the GitLab application and is often confused with the GitLab Runner. Thus, [Task Runner will be renamed to Toolbox](https://gitlab.com/groups/gitlab-org/charts/-/epics/25).

data/deprecations/serverless.yml

 - name: "GitLab Serverless"
   announcement_milestone: "14.3"
+  announcement_date: "2021-09-22"
   removal_milestone: "15.0"
   body: |
     [GitLab Serverless](https://docs.gitlab.com/ee/user/project/clusters/serverless/) is a feature set to support Knative-based serverless development with automatic deployments and monitoring.

data/deprecations/templates/_deprecation_template.md.erb

@@ -22,6 +22,8 @@ then run `bin/rake gitlab:docs:compile_deprecations`.
 ### <%= deprecation["name"]%>
 
 <%= deprecation["body"] -%>
+
+Announced: <%= deprecation["announcement_date"]%>
     <%- end -%>
   <%- end -%>
 <%- else -%>

data/deprecations/templates/example.yml

@@ -12,7 +12,8 @@
 
 - name: "Feature name" # The name of the feature to be deprecated
   announcement_milestone: "XX.YY" # The milestone when this feature was first announced as deprecated.
-  removal_milestone: "XX.YY" # the milestone when this feature is planned to be removed
+  announcement_date: "YYYY-MM-DD" # The date of the milestone release when this feature was first announced as deprecated
+  removal_milestone: "XX.YY" # The milestone when this feature is planned to be removed
   body: | # Do not modify this line, instead modify the lines below.
     <!-- START OF BODY COMMENT
 
@@ -29,5 +30,4 @@
   documentation_url: # (optional) This is a link to the current documentation page
   image_url: # (optional) This is a link to a thumbnail image depicting the feature
   video_url: # (optional) Use the youtube thumbnail URL with the structure of https://img.youtube.com/vi/UNIQUEID/hqdefault.jpg
-  announcement_date: # YYYY-MM-DD format - the date of the milestone release when this feature was first announced as deprecated
   removal_date: # (optional - may be required in the future) YYYY-MM-DD format - the date of the milestone release when this feature is planned to be removed

doc/update/deprecations.md

@@ -26,6 +26,8 @@ supported using a single PostgreSQL adapter, whereas the new format is changing
 
 This deprecation mainly impacts users compiling GitLab from source because Omnibus will handle this configuration automatically.
 
+Announced: 2021-09-22
+
 ### Audit events for repository push events
 
 Audit events for [repository events](../administration/audit_events.md#repository-push) are now deprecated and will be removed in GitLab 15.0.
@@ -34,6 +36,8 @@ These events have always been disabled by default and had to be manually enabled
 feature flag. Enabling them can cause too many events to be generated which can
 dramatically slow down GitLab instances. For this reason, they are being removed.
 
+Announced: 2021-09-02
+
 ### OmniAuth Kerberos gem
 
 The `omniauth-kerberos` gem will be removed in our next major release, GitLab 15.0.
@@ -42,12 +46,16 @@ This gem has not been maintained and has very little usage. We therefore plan to
 
 Note that we are not deprecating the Kerberos SPNEGO integration, only the old password-based Kerberos integration.
 
+Announced: 2021-09-22
+
 ### GitLab Serverless
 
 [GitLab Serverless](../user/project/clusters/serverless/index.md) is a feature set to support Knative-based serverless development with automatic deployments and monitoring.
 
 We decided to remove the GitLab Serverless features as they never really resonated with our users. Besides, given the continuous development of Kubernetes and Knative, our current implementations do not even work with recent versions.
 
+Announced: 2021-09-22
+
 ## 14.4
 
 ### Rename Task Runner pod to Toolbox
@@ -55,3 +63,5 @@ We decided to remove the GitLab Serverless features as they never really resonat
 The Task Runner pod is used to execute periodic housekeeping tasks within the GitLab application and is often confused with the GitLab Runner. Thus, [Task Runner will be renamed to Toolbox](https://gitlab.com/groups/gitlab-org/charts/-/epics/25).
 
 This will result in the rename of the sub-chart: `gitlab/task-runner` to `gitlab/toolbox`. Resulting pods will be named along the lines of `{{ .Release.Name }}-toolbox`, which will often be `gitlab-toolbox`. They will be locatable with the label `app=toolbox`.
+
+Announced: 2021-09-22