Index and contents point to last used help page.

When clicking on 'index' or 'contents' you'll get the last loaded help page, not the one you wanted.

100% repro:

1. open ANY other help page
2. close Qt DS
3. open Qt DS
4. select 'Help' -> 'Index' or 'Contents'

It needs to be reseached how to hardlink certain chapters to the index and contents menu items in Qt DS.