added new readme in the directory

docs/source/whatsnew/pr/README.md

@@ -0,0 +1,17 b''
+Documenting What's New
+----------------------
+
+When making a new pull request that either adds a new feature, or makes a
+backwards-incompatible change to IPython, please add a new `.rst` file in this
+directory documenting this change as a part of your Pull Request.
+
+This will allow multiple Pull Requests to do the same without conflicting with
+one another. Periodically, IPython developers with commit rights will run a
+script and populate [developement.rst](../developement.rst)  with the contents
+of this directory, and clean it up.
+
+Files which describe new features can have any name, such as
+`antigravity-feature.rst`, whereas backwards incompatible changes should have a
+filename of `incompat-switching-to-perl.rst`. Our "What's new" files always have
+two sections,  and this prefix scheme will make sure that the backwards
+incompatible changes get routed to their proper section.