Reimplement announcements (#21586)

* Reimplement announcements

Signed-off-by: Celeste Horgan <celeste@cncf.io>

Address deprecation-warning styling

Signed-off-by: Celeste Horgan <celeste@cncf.io>

Use partial only

Signed-off-by: Celeste Horgan <celeste@cncf.io>

Refine

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* Turn on announcements for preview only

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* Update config.toml

Co-authored-by: Celeste Horgan <celeste@cncf.io>

Co-authored-by: Zach Corleissen <zacharysarah@users.noreply.github.com>

i18n/en.toml

@@ -1,5 +1,10 @@
 # i18n strings for the English (main) site.
 # NOTE: Please keep the entries in alphabetical order when editing
+[announcement_title]
+other = "Black lives matter."
+
+[announcement_message]
+other = "We stand in solidarity with the Black community.<br/>Racism is unacceptable.<br/> It conflicts with the [core values of the Kubernetes project](https://git.k8s.io/community/values.md) and our community does not tolerate it."
 
 [caution]
 other = "Caution:"
@@ -28,6 +33,9 @@ other = "Twitter"
 [community_youtube_name]
 other = "YouTube"
 
+[deprecation_title]
+other = "You are viewing documentation for Kubernetes version:"
+
 [deprecation_warning]
 other = " documentation is no longer actively maintained. The version you are currently viewing is a static snapshot. For up-to-date documentation, see the "