updated README
Modified qt/downloaddemodipydocs.cpp

In DownloadDemoDipydocs::DownloadDemoDipydocs(), set progress.setMinimumDuration
to 0, hoping it will solve the problem of the download window not appearing,
even for long downloads.
Merge branch 'feature147' into dev

Modified qt/downloaddemodipydocs.cpp

In DownloadDemoDipydocs::DownloadDemoDipydocs(), set progress.setMinimumDuration
to 0, hoping it will solve the problem of the download window not appearing,
even for long downloads.