Update plan.md.
Update plan.md.
rgbkrk/nteract,jdfreder/nteract,jdfreder/nteract,nteract/composition,rgbkrk/nteract,nteract/composition,nteract/nteract,nteract/nteract,jdfreder/nteract,nteract/nteract,nteract/nteract,jdfreder/nteract,rgbkrk/nteract,nteract/nteract,nteract/composition,rgbkrk/nteract,rgbkrk/nteract