User guide layout (#5016)

- Modified CSS: font-size, colors, margins...

- Added an ArticleContent Component that will be used for the changelog
and user guide articles, which contains the styles for each titles,
paragraphs, images etc.

- Added link to User Guide in footer

- Added a UserGuideWarning Component: 

<img width="332" alt="Screenshot 2024-04-17 at 18 14 48"
src="https://github.com/twentyhq/twenty/assets/102751374/0f5c601b-a2c0-4c63-baeb-1990d65fc332">

- Added a UserGuideEditContent Component:

<img width="394" alt="Screenshot 2024-04-17 at 18 16 24"
src="https://github.com/twentyhq/twenty/assets/102751374/6c7c3bd4-c5bb-4d02-8f93-bd99bc30ce7b">

- Added a UserGuideLink Component (for usage in MDX to allow links to
open in new tab)

- Fixed table of content

- Made responsive

---------

Co-authored-by: Ady Beraud <a.beraud96@gmail.com>
Co-authored-by: Félix Malfait <felix.malfait@gmail.com>

packages/twenty-website/src/app/_server-utils/get-posts.tsx

@@ -6,6 +6,10 @@ import path from 'path';
 import rehypeSlug from 'rehype-slug';
 import gfm from 'remark-gfm';
 
+import ArticleEditContent from '@/app/_components/ui/layout/articles/ArticleEditContent';
+import ArticleLink from '@/app/_components/ui/layout/articles/ArticleLink';
+import ArticleWarning from '@/app/_components/ui/layout/articles/ArticleWarning';
+
 interface ItemInfo {
   title: string;
   position?: number;
@@ -103,6 +107,17 @@ export async function compileMDXFile(filePath: string, addToc = true) {
   const fileContent = fs.readFileSync(filePath, 'utf8');
   const compiled = await compileMDX<{ title: string; position?: number }>({
     source: fileContent,
+    components: {
+      ArticleWarning(properties) {
+        return <ArticleWarning {...properties} />;
+      },
+      ArticleEditContent(properties) {
+        return <ArticleEditContent {...properties} />;
+      },
+      ArticleLink(properties) {
+        return <ArticleLink {...properties} />;
+      },
+    },
     options: {
       parseFrontmatter: true,
       mdxOptions: {