Added some guff to the README

README.md

@@ -6,11 +6,37 @@ NOTE! I am LEARNING. This is not an example of how to do it.
 
 ## Usage
 
-FIXME
+The state of the machine is represented by a structure which is passed around between functions.
+
+So you can make a machine with make-default-machine:
+
+  vending.repl=> (make-default-machine)
+  {:tendered nil, :output nil, :coins {:plack 4, :merk 1, :bawbee 4, :bodle 4}, :change nil, :stock {:teacake 5, :caramel-wafer 5, :snowball 5}, :message ""}
+
+You can add coins to it with add-coin; as this is a Scots machine the coins you can add are merks, placks, bawbees and bodles.
+
+  vending.repl=> (add-coin (add-coin *1 :merk) :bawbee)
+  {:message "Added a :bawbee", :tendered (:bawbee :merk), :output nil, :coins {:plack 4, :merk 1, :bawbee 4, :bodle 4}, :change nil, :stock {:teacake 5, :caramel-wafer 5, :snowball 5}}
+
+The machine serves good Scottish super-foods: caramel wafers, teacakes and snowballs. To get a teacake, try
+
+  vending.repl=> (get-teacake *1)
+  {:message "Enjoy your :teacake", :coins {:merk 2, :plack 4, :bawbee 4, :bodle 4}, :change (:bawbee), :output (:teacake), :stock {:teacake 4, :caramel-wafer 5, :snowball 5}}
+
+There's very little error checking; if you try to add a dollar, I've no idea what will happen but it probably won't be good.
+
+Finally if you add coins and decide you want them back, you can use coin-return:
+
+  vending.repl=> (coin-return (add-coin (add-coin (make-default-machine) :merk) :plack))
+  {:message "Coins returned", :output nil, :coins {:plack 4, :merk 1, :bawbee 4, :bodle 4}, :change (:plack :merk), :stock {:teacake 5, :caramel-wafer 5, :snowball 5}}
+
+## Possible future development
+
+My panned next phase for this is to make it drive an interactive web page, first entirely server-side, and then, if that works, client-side.
 
 ## License
 
-Copyright © 2014 FIXME
+Copyright © 2014 Simon Brooke, Ali King and others
 
 Distributed under the Eclipse Public License either version 1.0 or (at
-your option) any later version.
+your option) any later version, simply because that's the default the package template gave us.