docs: add introduction section

docs/preview/01-index.md

@@ -6,28 +6,16 @@ slug: /
 sidebar_label: Welcome
 ---
 
-# Installation
+# Introduction
+Arcus BackgroundJobs provides common repeated background tasks that strengthen an application. This goes from automatic secret invalidation of Azure Key Vault secrets to publish an event on Azure EventGrid upon a potential expired client secret in Azure. This collection of background tasks has grown from real-life application builders that wanted to re-use existing functionality in a safe and trusted manner.
 
+# Installation
 The Arcus BackgroundJobs can be installed via NuGet, for example:
 
 ```shell
 PM > Install-Package Arcus.BackgroundJobs.CloudEvents
 ```
 
-# Features
-
-- **General**
-    - [Securely Receive CloudEvents](./02-Features/01-General/receive-cloudevents-job.md)
-- **Azure Active Directory**
-    - [Check Applications in Azure Active Directory for client secrets that have expired or will expire in the near future](./02-Features/04-AzureActiveDirectory/client-secret-expiration-job.md)
-- **Azure App Configuration**
-    - [Automatically refresh configuration values from Azure App Configuration](./02-Features/05-AzureAppConfiguration/auto-refresh-app-configuration.md)
-- **Databricks**
-    - [Measure Databricks job run outcomes as metric](./02-Features/03-Databricks/job-metrics.md)
-    - [Interact with Databricks to gain insights](./02-Features/03-Databricks/gain-insights.md)
-- **Security**
-    - [Automatically invalidate cached secrets from Azure Key Vault](./02-Features/02-Security/auto-invalidate-secrets.md)
-
 # License
 This is licensed under The MIT License (MIT). Which means that you can use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the web application. But you always need to state that Codit is the original author of this web application.
 

docs/versioned_docs/version-v0.4.0/01-index.md

@@ -6,28 +6,16 @@ slug: /
 sidebar_label: Welcome
 ---
 
-# Installation
+# Introduction
+Arcus BackgroundJobs provides common repeated background tasks that strengthen an application. This goes from automatic secret invalidation of Azure Key Vault secrets to publish an event on Azure EventGrid upon a potential expired client secret in Azure. This collection of background tasks has grown from real-life application builders that wanted to re-use existing functionality in a safe and trusted manner.
 
+# Installation
 The Arcus BackgroundJobs can be installed via NuGet, for example:
 
 ```shell
 PM > Install-Package Arcus.BackgroundJobs.CloudEvents
 ```
 
-# Features
-
-- **General**
-    - [Securely Receive CloudEvents](./02-Features/01-General/receive-cloudevents-job.md)
-- **Azure Active Directory**
-    - [Check Applications in Azure Active Directory for client secrets that have expired or will expire in the near future](./02-Features/04-AzureActiveDirectory/client-secret-expiration-job.md)
-- **Azure App Configuration**
-    - [Automatically refresh configuration values from Azure App Configuration](./02-Features/05-AzureAppConfiguration/auto-refresh-app-configuration.md)
-- **Databricks**
-    - [Measure Databricks job run outcomes as metric](./02-Features/03-Databricks/job-metrics.md)
-    - [Interact with Databricks to gain insights](./02-Features/03-Databricks/gain-insights.md)
-- **Security**
-    - [Automatically invalidate cached secrets from Azure Key Vault](./02-Features/02-Security/auto-invalidate-secrets.md)
-
 # License
 This is licensed under The MIT License (MIT). Which means that you can use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the web application. But you always need to state that Codit is the original author of this web application.