Add Monoid CE example.

FSharpx.Extras.sln

@@ -12,9 +12,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "docs", "docs", "{A6A6AF7D-D
 	ProjectSection(SolutionItems) = preProject
 		docs\DiningPhilosophers.fsx = docs\DiningPhilosophers.fsx
 		docs\index.fsx = docs\index.fsx
+		docs\MonoidCESample.fsx = docs\MonoidCESample.fsx
 		docs\Santa.fsx = docs\Santa.fsx
-		docs\StmSample.fsx = docs\StmSample.fsx
 		docs\StateSample.fsx = docs\StateSample.fsx
+		docs\StmSample.fsx = docs\StmSample.fsx
 		docs\StructuredFormatSample.fsx = docs\StructuredFormatSample.fsx
 		docs\UndoSample.fsx = docs\UndoSample.fsx
 		docs\WebProxy.fsx = docs\WebProxy.fsx

docs/MonoidCESample.fsx

@@ -0,0 +1,21 @@
+#r @"../bin/FSharpx.Extras.dll"
+#r @"../bin/FSharpx.Collections.dll"
+
+open FSharpx
+
+// Sample monoid implementation
+let addition = Monoid.sum()
+
+// Using monoids computation expression capabilities
+let x : float =
+    addition {
+        yield 1.0
+        yield 5.0
+        yield 6.0
+    }
+
+// Getting the zero
+let zero : float =
+    addition {
+        ()
+    }