doc: Update README.md

Author: jaywcjlove

core/README-zh.md

@@ -99,3 +99,6 @@ ReactDOM.render(<Demo />, _mount_);
 | collapsedWidth | 收缩宽度，设置为 `0` | boolean | `80` |
 | width | 宽度 | number/string | 200 |
 
+### License
+
+Licensed under the MIT License.

core/README.md

@@ -103,3 +103,6 @@ The layout wrapper, in which `Header` `Sider` `Content` `Footer` or `Layout` its
 | collapsedWidth | Width of the collapsed sidebar, by setting to 0 a special trigger will appear | boolean | `80` |
 | width | Width of the sidebar | number/string | 200 |
 
+### License
+
+Licensed under the MIT License.