Website UI design (#4829)

**Fixed different issues** :
 
- Multiple CSS fixes: font-size, colors, margins, z-index ...
- Fixed hover on contributor avatars
- Added link to contributors in footer
- Made the year in the footer dynamic (2023 --> 2024)
- Added name of contributor in "Thank you" section of Contributor page
- Added footer in small screens
- Made Activity Log Responsive 
- Fixed bug in "saving issues to DB", title was null everywhere. I
needed to implement an "upsert" behaviour to update the existing
database on init

**To be noted :** 

There is the following bug on production happening on mobile when you
refresh a second time :

<img width="1440" alt="Screenshot 2024-04-05 at 01 30 58"
src="https://github.com/twentyhq/twenty/assets/102751374/b935b07a-63dc-463d-8dcb-070ad4ef6db0">


It seems to be related to the following issue on mdx :
[https://github.com/hashicorp/next-mdx-remote/issues/350](https://github.com/hashicorp/next-mdx-remote/issues/350)

I added the following code that fixed this bug for me in development
(this needs to be tested in production) :

```
const serialized = await serialize(content, {
    mdxOptions: {
      development: process.env.NODE_ENV === 'development',
    }
  })
```

---------

Co-authored-by: Ady Beraud <a.beraud96@gmail.com>

packages/twenty-website/src/database/database.ts

@@ -76,10 +76,25 @@ const findAll = (model: SQLiteTableWithColumns<any>) => {
 const insertMany = async (
   model: SQLiteTableWithColumns<any>,
   data: any,
-  options?: { onConflictKey?: string },
+  options?: {
+    onConflictKey?: string;
+    onConflictUpdateObject?: any;
+  },
 ) => {
   if (isSqliteDriver) {
     const query = sqliteDb.insert(model).values(data);
+
+    if (options?.onConflictUpdateObject) {
+      if (options?.onConflictKey) {
+        return query
+          .onConflictDoUpdate({
+            target: [model[options.onConflictKey]],
+            set: options.onConflictUpdateObject,
+          })
+          .execute();
+      }
+    }
+
     if (options?.onConflictKey) {
       return query
         .onConflictDoNothing({
@@ -87,10 +102,23 @@ const insertMany = async (
         })
         .execute();
     }
+
     return query.execute();
   }
   if (isPgDriver) {
     const query = pgDb.insert(model).values(data);
+
+    if (options?.onConflictUpdateObject) {
+      if (options?.onConflictKey) {
+        return query
+          .onConflictDoUpdate({
+            target: [model[options.onConflictKey]],
+            set: options.onConflictUpdateObject,
+          })
+          .execute();
+      }
+    }
+
     if (options?.onConflictKey) {
       return query
         .onConflictDoNothing({