Update README.md

Author: wangkuiyi

README.md

@@ -1,18 +1,18 @@
-# Fluid
+# Couler for Google Tekton
 
-Fluid is a Python package allowing users to write [Tekton](https://github.com/tektoncd/pipeline) workflows in Python other than YAML.
+Couler is a Python package allowing users to write [Tekton](https://github.com/tektoncd/pipeline) workflows in Python other than YAML.
 
 Here is an example.  To the left is a Python program defining a Task and related TaskRun.  To the right is the equivalent YAML file.
 
 <table><tr><td valign=top>
 
 ```python
-import fluid
+import fluid as couler
 
-@fluid.task
+@couler.task
 def echo_hello_world(hello, world="El mundo"):
-    fluid.step(image="ubuntu", cmd=["echo"], args=[hello])
-    fluid.step(image="ubuntu", cmd=["echo"], args=[world])
+    couler.step(image="ubuntu", cmd=["echo"], args=[hello])
+    couler.step(image="ubuntu", cmd=["echo"], args=[world])
 ```
 
 </td><td valign=top>