Added a quick README.txt into the examples folder

Author: sfeister

examples/README.txt

@@ -0,0 +1,12 @@
+README FOR '[PRaLine]/examples/' DIRECTORY
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This directory contains example intermediate files (test_input.p, test_input.txt) for re-creating some of the plots of Graziani et al. 2017.
+
+More information on using and interpreting these examples can be found in the main documentation for PRaLine, located in the directory above at '[PRaLine]/README.md'.
+
+As described in the main documentation, analysis of the file can be performed via the command line:
+   lin-analyze test_input.p
+   lin-reconstruct test_input.p
+
+The plots generated (after 4000 iterations) after calling these functions should match those in the '[PRaLine]/examples/reference_images' directory.