message: docs(theming): explain where to place CSS variables
diff: @@ -15,6 +15,8 @@ Ionic components are built with <a href="https://developer.mozilla.org/en-US/doc
  CSS variables can be set globally in an application in the `:root` selector. They can also be applied only for a specific mode. See [Ionic Variables](#ionic-variables) for more information on the global variables Ionic provides.
  +When using the Ionic CLI to start an Angular project, the `src/theme/variables.scss` file is created where you can override the default Ionic Variables.
  +
  ```css
  /* Set variables for all modes */
  :root {
  