Update installation

Author: davidkpiano

docs/installation.mdx

@@ -13,15 +13,15 @@ You can install XState using your favorite package manager or embed the `<script
 <TabItem value="yarn" label="yarn">
 
 ```bash
-yarn add xstate
+yarn add xstate@beta
 ```
 
 </TabItem>
 
 <TabItem value="npm" label="npm">
 
 ```bash
-npm install xstate
+npm install xstate@beta
 ```
 
 </TabItem>
@@ -50,64 +50,3 @@ actor.subscribe((state) => {
 });
 actor.start();
 ```
-
-Coming soon… Codepen link.
-
-## Exports
-
-```ts
-import { doneInvoke, forwardTo, sendParent, sendTo } from './actions.ts';
-export { assign } from './actions/assign.ts';
-export { cancel } from './actions/cancel.ts';
-export { choose } from './actions/choose.ts';
-export { log } from './actions/log.ts';
-export { pure } from './actions/pure.ts';
-export { raise } from './actions/raise.ts';
-export { stop } from './actions/stop.ts';
-import { createActor, Actor, ActorStatus } from './interpreter.ts';
-import { createMachine } from './Machine.ts';
-import { mapState } from './mapState.ts';
-import { State } from './State.ts';
-import { StateNode } from './StateNode.ts';
-export { SimulatedClock } from './SimulatedClock.ts';
-export { StateMachine } from './StateMachine.ts';
-export { getStateNodes } from './stateUtils.ts';
-export { waitFor } from './waitFor.ts';
-export * from './typegenTypes.ts';
-export * from './types.ts';
-
-export {
-  matchesState,
-  pathToStateValue,
-  toObserver,
-  toSCXMLEvent,
-} from './utils.ts';
-export {
-  StateNode,
-  State,
-  mapState,
-  sendTo,
-  sendParent,
-  forwardTo,
-  createActor,
-  Actor,
-  ActorStatus,
-  doneInvoke,
-  createMachine,
-};
-export {
-  fromPromise,
-  fromObservable,
-  fromCallback,
-  fromEventObservable,
-  fromTransition,
-} from './actors/index.ts';
-
-export { stateIn, not, and, or } from './guards.ts';
-
-declare global {
-  interface SymbolConstructor {
-    readonly observable: symbol;
-  }
-}
-```