Update Features of WPS Office on 10/17/2019

Important features:

1. PDF supports text and image editing, as well as page insertion, replacement and extraction.

2. PDF supports text annotation, freehand drawing and whiteout functions.

3. PDF supports header/footer and page number editing.

4. PDF supports watermark insertion and document encryption.

5. PDF supports annotation mode.

6. Optimized PDF browsing experience for smoother page scrolling/zooming.

7. New MathEdit formula editor.

8. Supports document sharing for more convenient document transmission.

9. More product pages adapted to dark mode.

10. Fixed some bugs and improved the stability of the application.