Update and simplify readme.
Update and simplify readme.

lyw07/kolibri,indirectlylit/kolibri,lyw07/kolibri,mrpau/kolibri,indirectlylit/kolibri,lyw07/kolibri,indirectlylit/kolibri,learningequality/kolibri,indirectlylit/kolibri,lyw07/kolibri,learningequality/kolibri,learningequality/kolibri,mrpau/kolibri,mrpau/kolibri,mrpau/kolibri,learningequality/kolibri