update reamdme.md

readme.md

@@ -19,6 +19,7 @@ Currently, the following editing operations are supported:
   - Delete a node and all the nodes rooted on it.
   - Recover a deleted node.
 - [x] Rename the name of node inputs/outputs
+- [x] Rename the model inputs/outputs
 - [x] Edit the attribute of nodes
 - [x] Add new nodes (experimental)
 
@@ -135,6 +136,9 @@ The process is shown in the following figure:
 
 <img src="./docs/rename_io.gif" style="zoom:75%;" />
 
+## Rename the name of node inputs/outputs
+Click the model input/output node, type a new name for it in the sidebar, then we are done.
+
 ## Edit the attribute of nodes
 
 Change the original attribute to a new value, then we are done.