Updated history of contribs in toc2 README

Author: jfbercher

src/jupyter_contrib_nbextensions/nbextensions/toc2/README.md

@@ -142,3 +142,8 @@ This option requires the IPython kernel and is not present with other kernels.
   + constrain draggable toc to the body
   + various bits of cleanup
   + add settings dialog for per-notebook metadata-stored settings
+- @jfbercher Feb 2018, Option to define a number to begin numbering with.
+- @jcb91 March 2018, Add controls for all per-notebook metadata options
+- @jfbercher December 2018, toc2 history. Moves into the toc2 history of jumps into the notebook, using the forward-back browser buttons.
+- @zthxxx, April 2018, fix toc2.js load failed with working in non-live notebook (with navigation menu enabled)
+- @jfbercher April 2018, Some export tuning