Regarding the configuring on Git
The link specifies the configuration of git.
I have a following query, should the configuration for git has to be done in project folder or globally , outside the project folder?
should the configuration for git has to be done in project folder or globally
I can see no technical reason why you would need to do this globally. However, if you do it locally, then you would need to do it for every Qt-related repo, and since Qt uses quite a number of separate repos, that might be a pain or just generally more error prone.
Once you push change requests upstream, there's no way for upstream repos to know if you used global or local config, just as long as the config with set correctly either way. So do what fits best with your development practices.
(It is possible, I suppose, that some git config variables are not valid locally, but I see no mention of anything like that in the
git help configoutput).