chore(background): update README.md

Signed-off-by: braks <[email protected]>

Author: bcakmakoglu

packages/background/README.md

@@ -1,6 +1,6 @@
 # Vue Flow: Background Component
 
-> [!WARNING] DEPRECATED
+> [!WARNING]
 > This package has been deprecated. Please use the `<Background>` component export directly from the core pkg `import { Background } from '@vue-flow/core'`
 
 This is a background component for Vue Flow.