This is just a simple plugin for krunner. It's basically useless, but it's the base from which you can start building your own plugins.
Main requirements should be installed with this command on Ubuntu:
sudo apt-get install extra-cmake-module libkf5i18n-dev libkf5service-dev libkf5textwidgets-dev libkf5runner-dev libkf5configwidgets-dev plasma-framework-dev
Anyway, Cmake could ask you to install other libraries.
In order to compile and install this plugin you should run these commands:
mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=`kf5-config --prefix` -DQT_PLUGIN_INSTALL_DIR=`kf5-config --qt-plugins`
make
sudo make install
kquitapp krunner
krunner
If you want something easier, there are install and uninstall scripts.