docs: add blogpost for announcing v1.21.1 (#886)

* docs: add release announcement post for v1.21.1

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(v1.21.1): small fixups

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(v1.21.1): spelling fixes

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs(v1.21.1): clarify that Bell is trash

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

check-spelling run (pull_request) for Xe/v1.21.1-blogpost

Signed-off-by: check-spelling-bot <check-spelling-bot@users.noreply.github.com>
on-behalf-of: @check-spelling <check-spelling-bot@check-spelling.dev>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>
Signed-off-by: check-spelling-bot <check-spelling-bot@users.noreply.github.com>

.devcontainer/devcontainer.json

@@ -21,7 +21,8 @@
         "golang.go",
         "unifiedjs.vscode-mdx",
         "a-h.templ",
-        "redhat.vscode-yaml"
+        "redhat.vscode-yaml",
+        "streetsidesoftware.code-spell-checker"
       ]
     }
   }