src: sharding cleanup and checkReady rewrite (#3393)

* src: Step 1 of who knows how many

* src: Remove accidentally committed test file

* src: Remove useless added property in package.json

* docs: Trailing spaces, come back >.>

* src: Buhbye uws, we will miss you..not!

* src: Move 'auto' shard selection from totalShardCount to shards

* src: tweak

* src: Filter out floats from shard IDs
You want half of a shard or what?

* src: Misc cleanup and bugfix for GUILD_BAN_ADD

* src: Rewrite checkReady

* src: Misse this while merging master into my branch

* typings: Bring these up to date

* typings: Forgot allReady event

* src: Don't checkReady if the shard isn't waiting for guilds

* src: Fix a possible bug for when the ws dies and the session becomes -1

* src: Hopefully fix last edge case that could case a shard to infinitely boot loop

* src: Rename totalShardCount to shardCount

* src: Small bugfix

* src: Correct error message for shardCount being imvalid

Co-Authored-By: bdistin <bdistin@gmail.com>

* src: Small tweaks

* src: If this doesn't fix the issues I'm gonna throw a brick at my PC

* src: I swear, STOP BREAKING

* src: *groans at a certain snake*

* src: Use undefined instead of null on destroy in close event

Setting it to null sets the close code to null, which causes a WebSocket error to be thrown. The error is thrown from WebSocket, although there is no connection alive. Fun times!

* src: @SpaceEEC's requested changes

* src: Remove zucc from discord.js

Discord is removing support for it, sooo... Bye bye

* src: Missed this

* src: Apply @kyranet's suggestions

Co-Authored-By: Antonio Román <kyradiscord@gmail.com>

* src: @kyranet's suggestions

* src: Remove pako, update debug messages
- Pako is officially gone from both enviroments
  Install zlib-sync on node.js if you want it
- Improve a few debug messages some more
- Discover that internal sharding works in browsers but please don't do that

docs/general/welcome.md

@@ -24,8 +24,8 @@ v12 is still very much a work-in-progress, as we're aiming to make it the best i
 Only use it if you are fond of living life on the bleeding edge.
 
 ## About
-discord.js is a powerful [Node.js](https://nodejs.org) module that allows you to interact with the
-[Discord API](https://discordapp.com/developers/docs/intro) very easily.
+discord.js is a powerful [Node.js](https://nodejs.org) module that allows you to easily interact with the
+[Discord API](https://discordapp.com/developers/docs/intro).
 
 - Object-oriented
 - Predictable abstractions
@@ -46,14 +46,13 @@ Using opusscript is only recommended for development environments where node-opu
 For production bots, using node-opus should be considered a necessity, especially if they're going to be running on multiple servers.
 
 ### Optional packages
-- [zlib-sync](https://www.npmjs.com/package/zlib-sync) for significantly faster WebSocket data inflation (`npm install zlib-sync`)
-- [zucc](https://www.npmjs.com/package/zucc) for significantly faster WebSocket data inflation (`npm install zucc`)
+- [zlib-sync](https://www.npmjs.com/package/zlib-sync) for faster WebSocket data inflation (`npm install zlib-sync`)
 - [erlpack](https://github.com/discordapp/erlpack) for significantly faster WebSocket data (de)serialisation (`npm install discordapp/erlpack`)
 - One of the following packages can be installed for faster voice packet encryption and decryption:
     - [sodium](https://www.npmjs.com/package/sodium) (`npm install sodium`)
     - [libsodium.js](https://www.npmjs.com/package/libsodium-wrappers) (`npm install libsodium-wrappers`)
-- [uws](https://www.npmjs.com/package/@discordjs/uws) for a much faster WebSocket connection (`npm install @discordjs/uws`)
-- [bufferutil](https://www.npmjs.com/package/bufferutil) for a much faster WebSocket connection when *not* using uws (`npm install bufferutil`)
+- [bufferutil](https://www.npmjs.com/package/bufferutil) for a much faster WebSocket connection (`npm install bufferutil`)
+- [utf-8-validate](https://www.npmjs.com/package/utf-8-validate) in combination with `bufferutil` for much faster WebSocket processing (`npm install utf-8-validate`)
 
 ## Example usage
 ```js