Make the content item the default one.
Make the content item the default one.

To make the addition of the qml docs more prominent, make the content
item the default one as it shows all available documentation sets.

Task-number: QTCREATORBUG-1024
Reviewed-by: kkoehne

renatofilho/QtCreator,richardmg/qtcreator,hdweiss/qt-creator-visualizer,syntheticpp/qt-creator,pcacjr/qt-creator,martyone/sailfish-qtcreator,syntheticpp/qt-creator,martyone/sailfish-qtcreator,syntheticpp/qt-creator,duythanhphan/qt-creator,KDAB/KDAB-Creator,colede/qtcreator,ostash/qt-creator-i18n-uk,xianian/qt-creator,farseerri/git_code,Distrotech/qtcreator,malikcjm/qtcreator,farseerri/git_code,hdweiss/qt-creator-visualizer,pcacjr/qt-creator,richardmg/qtcreator,yinyunqiao/qtcreator,jonnor/qt-creator,dmik/qt-creator-os2,xianian/qt-creator,yinyunqiao/qtcreator,KDE/android-qt-creator,dmik/qt-creator-os2,maui-packages/qt-creator,AltarBeastiful/qt-creator,AltarBeastiful/qt-creator,jonnor/qt-creator,kuba1/qtcreator,richardmg/qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,azat/qtcreator,yinyunqiao/qtcreator,farseerri/git_code,KDE/android-qt-creator,ostash/qt-creator-i18n-uk,danimo/qt-creator,hdweiss/qt-creator-visualizer,ostash/qt-creator-i18n-uk,Distrotech/qtcreator,azat/qtcreator,malikcjm/qtcreator,darksylinc/qt-creator,bakaiadam/collaborative_qt_creator,martyone/sailfish-qtcreator,farseerri/git_code,amyvmiwei/qt-creator,pcacjr/qt-creator,bakaiadam/collaborative_qt_creator,colede/qtcreator,renatofilho/QtCreator,kuba1/qtcreator,Distrotech/qtcreator,kuba1/qtcreator,KDE/android-qt-creator,kuba1/qtcreator,darksylinc/qt-creator,yinyunqiao/qtcreator,Distrotech/qtcreator,kuba1/qtcreator,malikcjm/qtcreator,ostash/qt-creator-i18n-uk,ostash/qt-creator-i18n-uk,Distrotech/qtcreator,jonnor/qt-creator,farseerri/git_code,amyvmiwei/qt-creator,renatofilho/QtCreator,hdweiss/qt-creator-visualizer,martyone/sailfish-qtcreator,xianian/qt-creator,kuba1/qtcreator,pcacjr/qt-creator,darksylinc/qt-creator,yinyunqiao/qtcreator,syntheticpp/qt-creator,bakaiadam/collaborative_qt_creator,KDAB/KDAB-Creator,dmik/qt-creator-os2,Distrotech/qtcreator,maui-packages/qt-creator,sandsmark/qtcreator-minimap,duythanhphan/qt-creator,azat/qtcreator,jonnor/qt-creator,xianian/qt-creator,ostash/qt-creator-i18n-uk,omniacreator/qtcreator,sandsmark/qtcreator-minimap,Distrotech/qtcreator,danimo/qt-creator,amyvmiwei/qt-creator,jonnor/qt-creator,dmik/qt-creator-os2,KDAB/KDAB-Creator,colede/qtcreator,KDE/android-qt-creator,malikcjm/qtcreator,renatofilho/QtCreator,hdweiss/qt-creator-visualizer,kuba1/qtcreator,maui-packages/qt-creator,maui-packages/qt-creator,AltarBeastiful/qt-creator,xianian/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,syntheticpp/qt-creator,richardmg/qtcreator,danimo/qt-creator,darksylinc/qt-creator,colede/qtcreator,duythanhphan/qt-creator,malikcjm/qtcreator,bakaiadam/collaborative_qt_creator,xianian/qt-creator,bakaiadam/collaborative_qt_creator,azat/qtcreator,AltarBeastiful/qt-creator,amyvmiwei/qt-creator,duythanhphan/qt-creator,azat/qtcreator,malikcjm/qtcreator,farseerri/git_code,syntheticpp/qt-creator,duythanhphan/qt-creator,colede/qtcreator,amyvmiwei/qt-creator,bakaiadam/collaborative_qt_creator,AltarBeastiful/qt-creator,ostash/qt-creator-i18n-uk,sandsmark/qtcreator-minimap,richardmg/qtcreator,xianian/qt-creator,malikcjm/qtcreator,KDE/android-qt-creator,omniacreator/qtcreator,renatofilho/QtCreator,martyone/sailfish-qtcreator,colede/qtcreator,AltarBeastiful/qt-creator,darksylinc/qt-creator,KDAB/KDAB-Creator,yinyunqiao/qtcreator,danimo/qt-creator,richardmg/qtcreator,maui-packages/qt-creator,renatofilho/QtCreator,sandsmark/qtcreator-minimap,omniacreator/qtcreator,danimo/qt-creator,KDAB/KDAB-Creator,omniacreator/qtcreator,KDE/android-qt-creator,colede/qtcreator,KDE/android-qt-creator,pcacjr/qt-creator,dmik/qt-creator-os2,duythanhphan/qt-creator,xianian/qt-creator,AltarBeastiful/qt-creator,danimo/qt-creator,xianian/qt-creator,dmik/qt-creator-os2,danimo/qt-creator,jonnor/qt-creator,dmik/qt-creator-os2,hdweiss/qt-creator-visualizer,richardmg/qtcreator,sandsmark/qtcreator-minimap,maui-packages/qt-creator,omniacreator/qtcreator,omniacreator/qtcreator,danimo/qt-creator,darksylinc/qt-creator,sandsmark/qtcreator-minimap,amyvmiwei/qt-creator,bakaiadam/collaborative_qt_creator,omniacreator/qtcreator,darksylinc/qt-creator,maui-packages/qt-creator,martyone/sailfish-qtcreator,kuba1/qtcreator,syntheticpp/qt-creator,AltarBeastiful/qt-creator,farseerri/git_code,kuba1/qtcreator,yinyunqiao/qtcreator,pcacjr/qt-creator,farseerri/git_code,KDAB/KDAB-Creator,amyvmiwei/qt-creator,amyvmiwei/qt-creator,darksylinc/qt-creator,duythanhphan/qt-creator,azat/qtcreator,KDE/android-qt-creator,pcacjr/qt-creator