Confusion about Shared Styles on Layer
Many people seemed to be confused (myself included) that you set and get a shared style from

```layer.sharedStyle```

See
- https://sketchplugins.com/d/1807-how-can-i-find-out-if-a-layer-style-deviates-from-its-shared-style
- https://sketchplugins.com/d/1810-how-to-get-shared-style-of-symbol-override

Can the documentation be updated so that is properly communicated?