message: Fix typo on architecture-overview.md
diff: @@ -249,7 +249,7 @@ however likely to change in the future.
  The common packages are the packages effectively depended on by all other pages.
  This is a much smaller set of packages but they are also very pervasive. Because
  the common packages are isomorphic and must execute both in the frontend and
  -backend, they are never allowed to depend on any of the frontend of backend
  +backend, they are never allowed to depend on any of the frontend or backend
  packages.
  The Backstage CLI is in a category of its own and is depended on by virtually
  