Fix imports for WebGLRenderer.d.ts

Missing imports for Geometry and BufferGeometry causes issues in typescript projects.

src/renderers/WebGLRenderer.d.ts

@@ -17,6 +17,8 @@ import { Fog } from './../scenes/Fog';
 import { ToneMapping, ShadowMapType, CullFace } from '../constants';
 import { WebVRManager } from '../renderers/webvr/WebVRManager';
 import { RenderTarget } from './webgl/WebGLRenderLists';
+import { Geometry } from './core/Geometry';
+import { BufferGeometry } from './core/BufferGeometry';
 
 export interface Renderer {
 	domElement: HTMLCanvasElement;