Add more docs for Feature Layer

not complete, but progress..

docs/features/custorders/receiving/index.rst

@@ -0,0 +1,15 @@
+
+Receiving
+=========
+
+In the context of Customer Orders, our concern here is making sure the
+Receiver knows about them and sets them aside while receiving the
+Purchase Order, once it's arrived from the Vendor.
+
+Another concern is how/when/who should contact the Customer to notify
+them that their order has arrived.  If the Customer account has a
+valid email address on file then perhaps they are emailed
+automatically; otherwise an Employee must call their phone number etc.
+In either case the *attempt* to contact the Customer should be
+recorded somehow, along with notes e.g. indicating if it was
+successful.