docs(WIP): Bring the main doc pages up to date, and add more examples (#2094)

* Bring some docs up to date, as well as add a new example

* Missed an exclamation mark

* Do requested changes

* Do suggestions

* Same suggestions for the other examples

* Show people that they can also use reply with embeds

* Typos in embed.js example

* Remove object example from embeds, too complex
Suggested by Yukine

* Some changes, some requested changes

* Add moderation examples!

* Add attachment examples

* Missing dot

* Fix spacing

* Requested Changes

* Quote consistency

* Tfw you break the syntax

docs/general/welcome.md

@@ -10,6 +10,7 @@
     <a href="https://www.npmjs.com/package/discord.js"><img src="https://img.shields.io/npm/dt/discord.js.svg?maxAge=3600" alt="NPM downloads" /></a>
     <a href="https://travis-ci.org/discordjs/discord.js"><img src="https://travis-ci.org/discordjs/discord.js.svg" alt="Build status" /></a>
     <a href="https://david-dm.org/discordjs/discord.js"><img src="https://img.shields.io/david/discordjs/discord.js.svg?maxAge=3600" alt="Dependencies" /></a>
+    <a href="https://www.patreon.com/discordjs"><img src="https://img.shields.io/badge/donate-patreon-F96854.svg" alt="Patreon" /></a>
   </p>
   <p>
     <a href="https://nodei.co/npm/discord.js/"><img src="https://nodei.co/npm/discord.js.png?downloads=true&stars=true" alt="NPM info" /></a>