Add redis to contributor guide (#7369)

## Context

We are adding redis to default twenty configuration. 

## What

1. This PR sets up the local setup for contributors accordingly

2. I'm also updating the code blocks guide:

Before:
<img width="921" alt="image"
src="https://github.com/user-attachments/assets/2203cc99-b5a5-4d05-a8b1-98a348aee9df">


After:
<img width="921" alt="image"
src="https://github.com/user-attachments/assets/5b3e6f34-723d-4309-888b-c02ce794891d">

packages/twenty-website/src/app/_components/ui/layout/articles/ArticleContent.tsx

@@ -1,7 +1,7 @@
 'use client';
 
-import { ReactNode } from 'react';
 import styled from '@emotion/styled';
+import { ReactNode } from 'react';
 
 import { Theme } from '@/app/_components/ui/theme/theme';
 import { wrapHeadingsWithAnchor } from '@/shared-utils/wrapHeadingsWithAnchor';
@@ -17,6 +17,21 @@ const StyledContent = styled.div`
     max-width: 100%;
     line-height: 1.8;
     color: black;
+    padding: 4px;
+    border-radius: 4px;
+    background: #1414140a;
+  }
+
+  pre {
+    background: #1414140a;
+    padding: 4px;
+    border-radius: 4px;
+
+    code {
+      padding: 0;
+      border-radius: 0;
+      background: none;
+    }
   }
 
   p {

packages/twenty-website/src/app/layout.css

@@ -124,9 +124,3 @@ strong,
     font-weight: 500;
     text-decoration: none;
 }
-
-code {
-    background: #1414140a;
-    padding: 4px;
-    border-radius: 4px;
-  }