Update app logo to v6.2.
Update screenshots to v20.
Update descriptions.

- Remove new tag for movie features
- Use clear "pay to unlock" instead of "X exclusive"
Remove crowdin mention from translations link.
Simplify shortcut description.
Update whypay page.

- Simplify and update feature explanations.
- Add notice that sub trial is not 30 days everywhere.
Update episode actions image.
Add sync fail section to help.
Merge branch 'gh-pages-dev' into gh-pages