update README

README.md

@@ -2,6 +2,15 @@
 
 Grass Mud Horse in Rust
 
+compile:
+```shell
+$ cargo b
+
+OR
+
+$ cargo b --release
+```
+
 help:
 ```shell
 $ ./target/debug/grassmudhorse -h
@@ -37,3 +46,9 @@ $ cat print-110.gmh | ./target/debug/grassmudhorse
 9
 10
 ```
+
+compile and execute:
+```shell
+$ ./target/debug/grassmudhorse --compile plus1100.gmh.source | ./target/debug/grassmudhorse
+5050
+```