adjust README

README

@@ -5,8 +5,15 @@ Beginnings of a PDF parser in Hammer
 
    https://gitlab.special-circumstanc.es/pesco/hammer/tree/pdf
 
+ - Help the default Makefile find Hammer
+
+       $ ln -s ../hammer/src hammer
+       $ ln -s ../hammer/build/opt/src lib
+
  - Build/Usage:
 
        $ make pdf
        $ ./pdf test.pdf
 
+       # place some test files in the t/ directory...
+       $ make test