docs: update README for cli changes

Author: antfu

README.md

@@ -71,9 +71,13 @@ npm install -g @wenyanlang/cli
 Try run the included examples, e.g.:
 
 ```bash
-wenyan examples/helloworld.wy -o helloworld.js
+wenyan examples/helloworld.wy
+# will outputs: 問天地好在。
 ```
 
+> From v0.1.0, the `wenyan` command will direct execute the script by default. If you are migrating from previous versions, please use `wenyan -h` to output the help and check [this PR](https://github.com/LingDong-/wenyan-lang) for the detailed changes.
+
+
 ### [The Online IDE](http://wenyan-lang.lingdong.works/ide.html)
 
 ![](screenshots/screenshot02.png)