docs(comments): add some comments

pkg/notify/slack.go

@@ -1,4 +1,3 @@
-// Package notify provides a simple interface to send notifications to Slack.
 package notify
 
 import (
@@ -15,7 +14,6 @@ import (
 	"terminalShop/pkg/models"
 )
 
-// slack client
 var slackClient = &http.Client{Timeout: 5 * time.Second}
 
 // dollars converts cents to dollars