docs(webhooks): Update installation webhook payload with missing fields

docs/integrations/integration-platform/webhooks/installation.mdx

@@ -27,6 +27,56 @@ A [public Sentry integration](/integrations/integration-platform/public-integrat
 - type: object
 - description: The installation
 
+### data['installation']['uuid']
+
+- type: string
+- description: The unique identifier for the installation
+
+### data['installation']['status']
+
+- type: string
+- description: The installation status, either `pending` (if "Verify Install" is enabled) or `installed`
+
+### data['installation']['app']
+
+- type: object
+- description: The Sentry app that was installed
+
+### data['installation']['app']['uuid']
+
+- type: string
+- description: The UUID of the Sentry app
+
+### data['installation']['app']['slug']
+
+- type: string
+- description: The slug of the Sentry app
+
+### data['installation']['app']['sentryAppId']
+
+- type: number
+- description: The numeric ID of the Sentry app
+
+### data['installation']['organization']
+
+- type: object
+- description: The organization the app was installed into
+
+### data['installation']['organization']['slug']
+
+- type: string
+- description: The slug of the organization
+
+### data['installation']['organization']['id']
+
+- type: number
+- description: The numeric ID of the organization
+
+### data['installation']['code']
+
+- type: string
+- description: The grant code used to obtain an auth token (only present when "Verify Install" is enabled and the installation status is `pending`)
+
 ## Payload
 
 ```json
@@ -41,11 +91,13 @@ A [public Sentry integration](/integrations/integration-platform/public-integrat
     "installation": {
       "status": "pending",
       "organization": {
-        "slug": "test-org"
+        "slug": "test-org",
+        "id": 1
       },
       "app": {
         "uuid": "2ebf071f-28df-4989-aca9-c37c763b278f",
-        "slug": "webhooks-galore"
+        "slug": "webhooks-galore",
+        "sentryAppId": 1
       },
       "code": "f3c71b491e3949b6b033ae45312a4fcb",
       "uuid": "a8e5d37a-696c-4c54-adb5-b3f28d64c7de"