update: readme

Author: eldesh

readme.md

@@ -101,12 +101,43 @@ foo_test.sml
 
 ### PolyML
 
-`PolyML.loadModule "/path/to/libsmlunit.poly"` for other project.
+To build, just `make`:
+
+```sh
+$ make -f Makefile.polyml
+echo "" | poly -q --error-exit --eval 'PolyML.suffixes := ".sig"::(!PolyML.suffixes)' \
+        --eval 'PolyML.make "src/main"' \
+        --use export.sml \
+        --eval 'PolyML.SaveState.saveModule ("libsmlunit.poly", SMLUnit)'
+Making main
+Making SMLUnit
+..
+Created structure SMLUnit
+```
+
+Then you will get `./libsmlunit.poly` which is the collection of SMLUnit entities that can be loaded.
 
 ```sh
 $ poly
 > PolyML.loadModule "/path/to/libsmlunit.poly";
+signature ASSERT =
+  sig
+..
+signature TESTRUNNER =
+  sig type parameter val runTest: parameter -> Test.test -> unit end
 val it = (): unit
->
 ```
 
+It is possible to loading directly to the REPL:
+
+```sh
+$ poly --eval 'PolyML.suffixes := ".sig"::(!PolyML.suffixes)'
+> PolyML.make "src/main";
+Making main
+Making SMLUnit
+..
+structure SMLUnit: SMLUNIT
+val it = (): unit
+```
+
+