Added a readme file.

README.rst

@@ -0,0 +1,12 @@
+Dependencies for `Playdoh <http://github.com/fwenzel/playdoh>`_.
+
+It goes something like this::
+
+    pip install --no-install --build=vendor/packages --src=vendor/src -I -r requirements/dev.txt
+    find packages src -type d -depth 1 >| vendor.pth
+
+    git init
+    for f in src/*; do
+        pushd $f >/dev/null && REPO=$(git config remote.origin.url) && popd > /dev/null && git submodule add $REPO $f
+        done
+    git add .