Add basic installation instructions

INSTALL.md

@@ -0,0 +1,8 @@
+INSTALL
+=======
+
+Currently gmon is in heavy development state, so there is no "official"
+installaion procedure.
+
+However, all that should suffice is to add *gmon/include* path to your
+**PYTHONPATH** and you should be able to run the *gmon/gmon* script.