[chore] update the comment of the component package (#9798)

Add connector as a type of component.

component/doc.go

@@ -4,5 +4,5 @@
 // Package component outlines the components used in the collector
 // and provides a foundation for the component’s creation and
 // termination process. A component can be either a receiver, exporter,
-// processor, or an extension.
+// processor, an extension, or a connector.
 package component // import "go.opentelemetry.io/collector/component"