add comment for #474

Author: xiantang

runner/engine.go

@@ -329,6 +329,8 @@ func (e *Engine) start() {
 				}
 			}
 
+			// cannot set buldDelay to 0, because when the write mutiple events received in short time
+			// it will start Multiple buildRuns: https://github.com/cosmtrek/air/issues/473
 			time.Sleep(e.config.buildDelay())
 			e.flushEvents()