Add warning about string array compatability (#147)

Author: musm

README.md

@@ -1,6 +1,6 @@
 ## MATLAB
 
-The `MATLAB.jl` package provides an interface for using [MATLAB™](http://www.mathworks.com/products/matlab/) from [Julia](http://julialang.org).  In other words, this package allows users to call MATLAB functions within Julia, thus making it easy to interoperate with MATLAB from the Julia language.
+The `MATLAB.jl` package provides an interface for using [MATLAB™](http://www.mathworks.com/products/matlab/) from [Julia](http://julialang.org) using the MATLAB C api.  In other words, this package allows users to call MATLAB functions within Julia, thus making it easy to interoperate with MATLAB from the Julia language.
 
 You cannot use `MATLAB.jl` without having purchased and installed a copy of MATLAB™ from [MathWorks](http://www.mathworks.com/). This package is available free of charge and in no way replaces or alters any functionality of MathWorks's MATLAB product.
 
@@ -12,6 +12,10 @@ Generally, this package is comprised of two aspects:
 
 * Communicating with MATLAB engine sessions
 
+**Warning**:
+MATLAB string arrays are not supported, and will throw an error exception. This also applies if they are nested within a MATLAB struct. This is a limitation of the MATLAB C api. The MATLAB function `convertContainedStringsToChars` may be used to facilitate conversion to a compatible format for use with `MATLAB.jl`.
+
+
 ## Installation
 
 **Important**: The procedure to setup this package consists of the following steps.