@uppy/core: mark `state` as deprecated (#3044)

packages/@uppy/core/src/index.js

@@ -279,8 +279,10 @@ class Uppy {
 
   /**
    * Back compat for when uppy.state is used instead of uppy.getState().
+   * @deprecated
    */
   get state () {
+    // Here, state is a non-enumerable property.
     return this.getState()
   }
 

packages/@uppy/core/types/index.d.ts

@@ -167,6 +167,7 @@ declare module Uppy {
     setOptions(update: Partial<UppyOptions>): void
     setState(patch: object): void
     getState<TMeta extends IndexedObject<any> = {}>(): State<TMeta>
+    /** @deprecated use `getState()` instead. */
     readonly state: State
     setFileState(fileID: string, state: object): void
     resetProgress(): void