Update readme for no .so

Install/Linux/README.txt

-This directory contains linux binaries for the glslang validator.  The main 
-executable is glslangValidator, which requires use of the shared object
-file libglsang.so.
+This directory contains a Linux binary for the glslang validator.
 
-Installation: Executing the ./install script will copy these to /usr/local/* 
-so that they may be executed from any directory.  
-
-Alternatively, you may put them where you wish, but will then need to use 
-something like:
-
-    export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:<path to libglslang.so>
+Installation: The executable in this directory is self sufficient, and can be 
+placed where desired; in a test directory, or in a system path, etc.
 
 Usage:  Execute glslangValidator with no arguments to get a usage statement.