fixed errors in TS files

examples/jsm/loaders/NRRDLoader.d.ts

@@ -17,7 +17,7 @@ export class NRRDLoader {
 
   load(url: string, onLoad: (group: Volume) => void, onProgress?: (event: ProgressEvent) => void, onError?: (event: ErrorEvent) => void): void;
   parse(data: string) : Volume;
-  parseChars(array: number[], start?: number, end?: number) : Volume;
+  parseChars(array: number[], start?: number, end?: number) : string;
   setPath(value: string) : this;
 
 }

examples/jsm/misc/VolumeSlice.d.ts

@@ -1,9 +1,9 @@
 import {
+  Matrix3,
   Mesh,
 } from '../../../src/Three';
 
 import { volume } from './Volume';
-import { Matrix3 } from '../../../build/three.module';
 
 export class VolumeSlice {
   constructor( volume: Volume, index?: number, axis?: string );