added chapter map to README

19-coroutine/coroutil.py

@@ -0,0 +1,12 @@
+# BEGIN CORO_DECO
+from functools import wraps
+
+def coroutine(func):
+    """Decorator: primes `func` by advancing to first `yield`"""
+    @wraps(func)
+    def primer(*args,**kwargs):  # <1>
+        gen = func(*args,**kwargs)  # <2>
+        next(gen)  # <3>
+        return gen  # <4>
+    return primer
+# END CORO_DECO