Added the illustrations for the user guide (#5409)

Added illustrations for all user-guide articles

packages/twenty-website/src/content/user-guide/api-webhooks.mdx

@@ -2,7 +2,7 @@
 title: API and Webhooks
 info: Learn how to manage API keys and Webhooks in Twenty.
 icon: IconApi
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/api/api.png
 ---
 
 ## API Keys

packages/twenty-website/src/content/user-guide/create-workspace.mdx

@@ -2,7 +2,7 @@
 title: Create a Workspace
 info: Follow a step-by-step guide on how to register on Twenty, choose a subscription plan, confirm your payment and set up your account, with additional advice on seeking assistance if needed.
 icon: IconNote
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/create-workspace/workspace-cover.png
 ---
 
 ## Step 1: Registration

packages/twenty-website/src/content/user-guide/fields.mdx

@@ -2,7 +2,7 @@
 title: Fields   
 info: Understand the role of fields and how to handle them.
 icon: IconChecklist
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/fields/field.png
 ---
 
 

packages/twenty-website/src/content/user-guide/glossary.mdx

@@ -2,7 +2,7 @@
 title: Glossary
 info: Get familiar with essential terminology used in Twenty.
 icon: IconVocabulary
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/glossary/glossary.png
 ---
 
 ## Company & People

packages/twenty-website/src/content/user-guide/import-export-data.mdx

@@ -2,7 +2,7 @@
 title: Import/Export Data
 info: Learn the procedures for importing and exporting data.
 icon: IconNote
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/import-export-data/cloud.png
 ---
 
 ## Import data

packages/twenty-website/src/content/user-guide/integrations.mdx

@@ -2,7 +2,7 @@
 title: Integrations
 info: Learn how to connect Twenty to your other tools.
 icon: IconBrandZapier
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/integrations/plug.png
 ---
 
 ## About

packages/twenty-website/src/content/user-guide/kanban-views.mdx

@@ -2,7 +2,7 @@
 title: Kanban Views
 info: Learn how to customize and navigate Kanban Views.
 icon: IconTargetArrow
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/kanban-views/kanban.png
 ---
 
 ## About Kanban Views

packages/twenty-website/src/content/user-guide/objects.mdx

@@ -2,7 +2,7 @@
 title: Objects
 info: Discover how to use standard and custom objects in your workspace.
 icon: IconChecklist
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/objects/objects.png
 ---
 
 ## Standard Objects

packages/twenty-website/src/content/user-guide/table-views.mdx

@@ -2,7 +2,7 @@
 title: Table Views
 info: Learn how to customize and navigate Table Views.
 icon: IconChecklist
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/table-views/table.png
 ---
 
 ## About Table Views

packages/twenty-website/src/content/user-guide/tips.mdx

@@ -2,7 +2,7 @@
 title: Tips 
 info: Discover tips and tricks for optimizing your experience, including user and workspace management, personalization settings, and navigation enhancements.
 icon: IconInfoCircle
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/tips/light-bulb.png
 ---
 
 ## Update workspace name & logo

packages/twenty-website/src/content/user-guide/views-sort-filter.mdx

@@ -2,7 +2,7 @@
 title: Views, Sort and Filter
 info: Find out how to create, manage and delete Object Views.
 icon: IconChecklist
-image: /images/user-guide/placeholder-header.png
+image: /images/user-guide/views/filter.png
 ---
 ## About Views