Update README.

README.md

@@ -11,3 +11,13 @@ That's where this application comes in.
 ### Why assembly?
 
 This application must not link against any libraries, ensuring it has no dependencies. That is easiest to do in assembly. The entirety of the application's functionality is to hang until a signal is received and this can be done easily with syscalls.
+
+Also, where else can you find a Docker container that occupies less than 1 KB on disk?
+
+### How do I use this?
+
+Assuming you have GNU Make and Docker installed, simply run:
+
+    make
+
+You will have a new binary named `hang` and it will be really small.