Introduce DiscordX (Discord.ts) for Slash Command Support (#209)

* Move commands to legacy folder.

* Setup DiscordX/Discord.ts

* Migrate CodeblockCommand to being a slash command.

* Fix tests which broke due to Discord.js changes.

* Install @types/node and remove debug code.

.eslintrc.js

@@ -12,6 +12,7 @@ module.exports = {
         }
     },
     rules: {
+        "new-cap": "off",
         "no-unused-vars": "off",
         "no-invalid-this": "off",
         "multiline-ternary": 0,

README.md

@@ -10,6 +10,7 @@ This repository contains the code for the CodeSupport Discord Bot. The project i
 
 ### Production
 - [Discord.js](https://www.npmjs.com/package/discord.js)
+- [DiscordX (formally Discord.ts)](https://www.npmjs.com/package/discordx)
 - [Axios](https://www.npmjs.com/package/axios)
 - [Twitter](https://www.npmjs.com/package/twitter)
 - [dotenv](https://www.npmjs.com/package/dotenv)