Import optimization example from potassco guide

potassco/hotel/opt.lp

@@ -0,0 +1,13 @@
+{ hotel(1..5) } = 1.
+star(1,5). cost(1,170).
+star(2,4). cost(2,140).
+star(3,3). cost(3,90).
+star(4,3). cost(4,75).  main_street(4).
+star(5,2). cost(5,60).
+noisy :- hotel(X), main_street(X).
+
+#maximize { Y@1, X : hotel(X), star(X, Y) }.
+#minimize { Y/Z@2, X : hotel(X), cost(X,Y), star(X, Z) }.
+:~ noisy. [ 1@3 ]
+
+#show hotel/1.