Made some updates to theme JSimple

[tangkunyin]

Updates list

update the previous theme information which were deprecated:

1. theme description.
2. theme tags which are now supported in the latest version in theme.
3. demo site link and new screenshot.

Do you have a test under the latest version of Hexo

Yes, I did it. Both English and Chinese were supported well.

Check List

• I want to publish my theme on Hexo official website.
  • I have read the theme publishing doc.
  • name is unique.
  • link URL is correct.
  • preview URL is correct.
  • preview URL web site is rendered correctly.
  • Add a screenshot to source/themes/screenshots.
  • Screenshot filename is same as value of name.
  • Screenshot size is 800 * 500.
  • Screenshot file format is png.

[github-actions]

Theme thumbnails validation completed.