docs: clarify getOnInit being false (#2391)

* docs: clarify that getOnInit should be set to true in an SPA if you want the stored value on initialization

* docs: add backticks

docs/utilities/storage.mdx

@@ -43,7 +43,7 @@ The `atomWithStorage` function creates an atom with a value persisted in `localS
 
 **options** (optional): an object with the following properties:
 
-- **getOnInit** (optional): A boolean value indicating whether to get item from storage on initialization.
+- **getOnInit** (optional, by default **false**): A boolean value indicating whether to get item from storage on initialization. Note that in an SPA with `getOnInit` either not set or `false` you will always get the initial value instead of the stored value on initialization. If the stored value is preferred set `getOnInit` to `true`.
 
 If not specified, the default storage implementation uses `localStorage` for storage/retrieval, `JSON.stringify()`/`JSON.parse()` for serialization/deserialization, and subscribes to `storage` events for cross-tab synchronization.