Changes in the README file to be better seen on https://invent.kde.org/plasma/plasma-pass

Changed the README file, so e.g. on https://invent.kde.org/plasma/plasma-pass it's seen:

cd plasma-pass  
mkdir build  
cd build  
cmake -DCMAKE_INSTALL_PREFIX=YOURPREFIX ..  
make  
make install  

instead of:

cd plasma-pass mkdir build cd build cmake -DCMAKE_INSTALL_PREFIX=YOURPREFIX .. make make install