Refs #1689 Added rst file for documentation

docs/source/algorithms/BASISReduction311-v1.rst

+.. algorithm::
+
+.. summary::
+
+.. alias::
+
+.. properties::
+
+For each property, the algorithm will remember the last value used. If user deletes
+this value and leaves blank the property field, the default value will be used. Default
+values are typical of the silicon311 reflection.
+
+Description
+-----------
+
+**Run numbers**:
+The syntax for the run numbers designation allows runs to be segregated
+into sets. The semicolon symbol ";" is used to separate the runs into sets.
+Runs within each set are jointly reduced.
+
+Examples:
+
+- 2144-2147,2149,2156  is a single set. All runs jointly reduced.
+
+- 2144-2147,2149;2156  is set 2144-2147,2149 and set 2156. The sets are reduced separately from each other.
+
+If *DoIndividual* is checked, then each run number is reduced separately
+from the rest. The semicolon symbol is ignored.
+
+**Momentum transfer binning scheme**: Three values are required, the
+lower boundary the bin with the minimum momentum, the bin width, and the
+upper boundary ofthe bin with the maximum momentum.
+
+Reflection Selector
+===================
+
+There are typical values for the properties of the 311 reflection:
+
++------------+----------------+------------------------+
+| Reflection |  Energy bins   | Momentum transfer bins |
+|            |   (micro-eV)   |   (inverse Angstroms)  |
++============+================+========================+
+| silicon311 | -740, 1.6, 740 |      0.5, 0.2, 3.7     |
++------------+----------------+------------------------+
+
+Also the following mask files is associated to the 311 reflection:
+
++-----------+------------------------------------------------------------------------------------------------+
+|Reflection | Mask file                                                                                      |
++===========+================================================================================================+
+|silicon311 | BASIS_Mask_OneQuarterRemains_SouthBottom.xml                                                   |
++-----------+------------------------------------------------------------------------------------------------+
+
+This mask files can be found in the SNS filesystem
+(**/SNS/BSS/shared/autoreduce/new_masks_08_12_2015/**)
+
+
+Usage
+-----
+
+.. warning::
+
+    This algorithm is not meant to be run from the command line.
+
+.. categories::
+
+.. sourcelink::
+