docs(store): add store docs (#23)

* docs(store): add store docs

* Update docs/reference/Store.md

---------

Co-authored-by: Vikas <[email protected]>
Co-authored-by: Corbin Crutchley <[email protected]>

docs/reference/Store.md

@@ -3,4 +3,72 @@ title: Store
 id: store
 ---
 
-Please see [/packages/store/src/index.ts](https://github.com/tanstack/store/tree/main/packages/store/src/index.ts)
+
+## `Store`
+
+A class that can be used to represent the entire application store. To create an instance of the store, you can use the constructor of the class.
+
+```tsx
+const store = new Store(initialState: TState, options?: StoreOptions<TState, TUpdater>)
+```
+
+### Constructor
+
+- `initialState: TState`: A required paremeter to instantiate the `Store` object. It represents a store that holds and manages state and provides subscription mechanisms.
+- `options?: StoreOptions<TState, TUpdater>`:  An optional parameter representing the options of the store. You can use this object to configure additional properties on your store.
+
+### Properties
+
+- `listeners`: A set of listeners subscribed to the store
+- `state`: The current state of the store.
+- `options?`: Options for configuring the store
+### Methods
+
+- `subscribe`: Subscribes a listener to the store. The method returns a function to unsubscribe the listener.
+
+  ```tsx
+  subscribe = (listener: Listener)
+  ``` 
+  - `listener` is a callback function that can be passed to subscribe to changes in the store.
+
+- `setState`: Updates the store's state using the provided updater function. 
+
+    ```tsx
+  setState = (
+    updater: TUpdater,
+    opts?:{
+      priority: Priority
+    })
+  ```
+
+  - `updater: TUpdater`: a function to update the store's state.
+  - `opts?`: An options object containing the update priority. Priority can be either `high` or `low`.
+
+- `batch`: Allows you to call `setState` multiple times in the callback while only notifying `listener`s of changes once per batched execution. 
+
+  ```tsx
+  batch = (cb: () => void)
+  ```
+
+## `StoreOptions`
+An interface representing the properties available to configure in Store.
+
+### Properties
+
+- `updateFn?`: A function to updates the current store's state.
+
+  ```tsx
+  updateFn?: (previous: TState) => (updater: TUpdater) => TState;
+  ```
+- `onSubscribe?`: A callback function called when a listener is subscribed to the store. Returns a function to unsubscribe the listener.
+  ```tsx
+  onSubscribe?: (
+    listener: Listener,
+    store: Store<TState, TUpdater>,
+  ) => () => void;
+  ```
+- `onUpdate?`: A callback function called when the store's state is updated.
+  ```tsx
+  onUpdate?: (opts: { priority: Priority }) => void;
+  ```
+- `defaultPriority?`: The default priority to use when no priority is specified.