Add basic edit handler for testing

djpianalto.com/goff/events/message_events.go

@@ -0,0 +1,11 @@
+package events
+
+import (
+	"fmt"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+func OnMessageEdit(session *discordgo.Session, m *discordgo.MessageEdit) {
+	fmt.Println(m.Content)
+}