Marketing improvements 3 (#3175)

* Improve marketing website

* User guide with icons

* Add TOC

* Linter

* Basic GraphQL playground

* Very basic contributors page

* Failed attempt to integrate REST playground

* Yarn

* Begin contributors DB

* Improve contributors page

packages/twenty-website/.eslintrc.json

@@ -1,3 +1,7 @@
 {
-  "extends": "next/core-web-vitals"
-}
+    "extends": [
+        "next/core-web-vitals",
+        "plugin:@typescript-eslint/recommended",
+        "plugin:prettier/recommended"
+    ]
+}