message: docs: update theme config
diff: @@ -396,8 +396,8 @@ The theme's config is to provide global settings that are used by different
  parts of the Chakra UI system.
  | Property | Description | Default |
  -| ------------------------ | ----------------------------------------------------------------------------------------------------------- | ------- |
  -| `cssVarsRoot` **(v1.4)** | The element to attach the css custom properties to | `:root` |
  +| -------------------------- | ----------------------------------------------------------------------------------------------------------- | -------- |
  +| `cssVarsPrefix` **(v1.4)** | The prefix to use for the generated CSS custom properties | `chakra` |
  | `initialColorMode` | The initial color mode your application should start with. <br reset/> Can be either `light` or `dark` mode | `light` |
  | `useSystemColorMode` | If `true`, the chakra system will update color mode <br reset/> based on your system preferences | `false` |
  @@ -407,7 +407,7 @@ property.
  ```jsx live=false
  const theme = extendTheme({
  config: {
  - cssVarsRoot: "body",
  + cssVarsPrefix: "ck",
  },
  })
  ```
  