README.md: explaining purpose of a dedicated section
README.md: explaining purpose of a dedicated section

bmwcarit/meta-ros,bulwahn/meta-ros,bmwcarit/meta-ros,simium/meta-ros,rapyuta/meta-ros,KristofRobot/meta-ros,bmwcarit/meta-ros,rapyuta/meta-ros,simium/meta-ros,KristofRobot/meta-ros,simium/meta-ros,bmwcarit/meta-ros,bulwahn/meta-ros,bulwahn/meta-ros,rapyuta/meta-ros