Adding build/install instructions.

README

@@ -1,7 +1,27 @@
                                 ocaml-glob
                                 ~~~~~~~~~~
 
+== Introduction
+
 This is a trivial wrapper around libc's glob(3) function for OCaml. The Glob
 module interface contains a single function, glob. This function takes a
 string argument possibly containing shell wildcards, and returns an array
 containing the names of the file system entries matching it.
+
+== Installation
+
+To build the bytecode library:
+
+  $ make
+
+To build the native code library:
+
+  $ make opt
+
+You can build both in a single step with
+
+  $ make reallyall
+
+To install, type
+
+  # make install