README: Mention support for bytecode and frozen bytecode.

README.md

@@ -22,7 +22,10 @@ Builtin modules include `sys`, `time`, and `struct`, etc. Select ports have
 support for `_thread` module (multithreading). Note that only a subset of
 Python 3 functionality is implemented for the data types and modules.
 
-See the repository www.github.com/micropython/pyboard for the MicroPython
+MicroPython can execute scripts in source form or precompiled to bytecode,
+either from on-device filesystem or "frozen" into MicroPython executable.
+
+See the repository http://github.com/micropython/pyboard for the MicroPython
 board (PyBoard), the officially supported reference electronic circuit board.
 
 Major components in this repository: