Added documentation to MSGDiffractionReduction

Refs #10215

Code/Mantid/docs/source/algorithms/MSGDiffractionReduction-v1.rst

@@ -0,0 +1,41 @@
+.. algorithm::
+
+.. summary::
+
+.. alias::
+
+.. properties::
+
+Description
+-----------
+
+The generic routing used to reduce diffraction runs from indirect inelastic geometry instruments at ISIS.
+
+Usage
+-----
+
+**Example - Running MSGDiffractionReduction.**
+
+.. testcode:: ExMSGDiffractionReductionSimple
+
+    MSGDiffractionReduction(InputFiles='IRS21360.raw',
+                            OutputWorkspaceGroup='DiffOut',
+                            Instrument='IRIS',
+                            Mode='diffspec',
+                            DetectorRange=[105,112])
+
+    ws = mtd['DiffOut'].getItem(0)
+
+    print 'Workspace name: %s' % ws.getName()
+    print 'Number of spectra: %d' % ws.getNumberHistograms()
+    print 'Number of bins: %s' % ws.blocksize()
+
+Output:
+
+.. testoutput:: ExMSGDiffractionReductionSimple
+
+    Workspace name: irs21360_diffspec_red
+    Number of spectra: 1
+    Number of bins: 1935
+
+.. categories::