Update docs

docs/development.md

@@ -39,14 +39,16 @@ chatbot.registerExtension({
 Here is an example of a simple extension that can be used to control a microscope.
 
 ```python
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 from imjoy_rpc import api
 
 class MoveStageInput(BaseModel):
+    """Move the microscope stage"""
     x: float = Field(..., description="x offset")
     y: float = Field(..., description="y offset")
 
 class SnapImageInput(BaseModel):
+    """Move the microscope stage"""
     exposure: float = Field(..., description="exposure time")
 
 def move_stage(kwargs):
@@ -84,4 +86,4 @@ async def setup():
     await chatbot.registerExtension(extension)
 
 api.export({"setup": setup})
-```
+```