docs(theming) list semantic-ui-less in dependencies (#4297)
docs(theming) list semantic-ui-less in dependencies (#4297)

With current documentation, compile will fail:

```
Failed to compile.
src/index.tsx
  Line 6:1:  'semantic-ui-less' should be listed in the project's dependencies, not devDependencies  import/no-extraneous-dependencies
```
Semantic-Org/Semantic-UI-React,Semantic-Org/Semantic-UI-React