doc: add guide for using slack integration in private channels

docs/documentation/platform/workflow-integrations/slack-integration.mdx

@@ -5,9 +5,11 @@ description: "Learn how to setup Slack integration"
 
 This guide will provide step by step instructions on how to configure Slack integration for your Infisical projects.
 
+## Setting up Slack integration in your projects
+
 <Tabs>
   <Tab title="Infisical Cloud">
-    ## Create Slack workflow integration
+    ### Create Slack workflow integration
     <Steps>
       <Step title="Navigate to the Workflow Integrations tab in your organization settings">
         In order to use Slack integration in your projects, you will first have to
@@ -32,7 +34,7 @@ This guide will provide step by step instructions on how to configure Slack inte
 
     </Steps>
 
-    ## Configure project to use Slack workflow integration
+    ### Configure project to use Slack workflow integration
 
     <Steps>
       <Step title="Navigate to the Workflow Integrations tab in the project settings">
@@ -56,7 +58,7 @@ This guide will provide step by step instructions on how to configure Slack inte
 
   </Tab>
   <Tab title="Self-hosted setup">
-    ## Configure admin settings
+    ### Configure admin settings
     Note that this step only has to be done once for the entire instance.
 
     <Steps>
@@ -90,7 +92,7 @@ This guide will provide step by step instructions on how to configure Slack inte
 
     </Steps>
 
-    ## Create Slack workflow integration
+    ### Create Slack workflow integration
 
     <Steps>
       <Step title="Navigate to the Workflow Integrations tab in your organization settings">
@@ -116,7 +118,7 @@ This guide will provide step by step instructions on how to configure Slack inte
 
     </Steps>
 
-    ## Configure project to use Slack workflow integration
+    ### Configure project to use Slack workflow integration
 
     <Steps>
       <Step title="Navigate to the Workflow Integrations tab in the project settings">
@@ -140,3 +142,23 @@ This guide will provide step by step instructions on how to configure Slack inte
 
   </Tab>
 </Tabs>
+
+## Using the Slack integration in your private channels
+
+<Steps>
+  <Step title="In the Apps section on Slack, find the Infisical app and view the app details">
+    ![private slack setup
+    menu](/images/platform/workflow-integrations/slack-integration/private-slack-setup-menu.png)
+  </Step>
+  <Step title="Select Add this app to a channel">
+    ![private slack setup
+    add](/images/platform/workflow-integrations/slack-integration/private-slack-setup-add.png)
+  </Step>
+  <Step title="Find the private channel you want to setup notifications for and press Add">
+    ![private slack setup
+    form](/images/platform/workflow-integrations/slack-integration/private-slack-setup-form.png)
+    You can now view the private channels in the Slack channel selection fields!
+    ![private slack setup
+    channels](/images/platform/workflow-integrations/slack-integration/private-slack-setup-channel-field.png)
+  </Step>
+</Steps>