Copy into wiki section re #7365

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

Code/Mantid/Framework/DataHandling/src/LoadInstrumentFromNexus.cpp

@@ -1,6 +1,13 @@
 /*WIKI* 
-
-
+    Attempts to load information about the instrument from a ISIS NeXus file. In particular attempt to
+    read L2 and 2-theta detector position values and add detectors which are positioned relative
+    to the sample in spherical coordinates as (r,theta,phi)=(L2,2-theta,0.0). Also adds dummy source
+    and samplepos components to instrument.
+    As this information appears to be absent from the existing NeXus Muon sample files, it seems that
+    little to this can be done at present. The new version of Muon nexus files may be more useful.
+
+    LoadInstrumentFromNexus is intended to be used as a child algorithm of
+    other Loadxxx algorithms, rather than being used directly.
 *WIKI*/
 //----------------------------------------------------------------------
 // Includes