[chore] cleaning

- removing old or commented code
- removing unused or deprecated types
- commenting everything, probably too much
- split msgEventHandler logic into methods
- readme update, removed most docs the pkg site looks good
- adjusted intents option, no need for a type

reaction.go

@@ -1,9 +1,9 @@
 package bolt
 
-// built-in Discord reactions
 type Reaction string
 
-// a few easy-to-use emojis, Discordgo/Discord API requires them to be saved like this.
+// a few easy-to-use emojis, Discordgo/Discord API requires them to be saved like this. Some appear "broken" but do not play friendly
+// when saved in-file
 const (
 	ReactionThumbsUp          Reaction = "👍"
 	ReactionThumbsDown        Reaction = "👎"