Auth: Add docs for the SSO Settings List endpoint (#80927)

* add docs for SSO Settings List endpoint

* Update docs/sources/developers/http_api/sso-settings.md

Co-authored-by: Misi <mgyongyosi@users.noreply.github.com>

* Update docs/sources/developers/http_api/sso-settings.md

Co-authored-by: Misi <mgyongyosi@users.noreply.github.com>

---------

Co-authored-by: Misi <mgyongyosi@users.noreply.github.com>

docs/sources/developers/http_api/sso-settings.md

@@ -24,6 +24,71 @@ title: SSO Settings API
 
 The API can be used to create, update, delete, get, and list SSO Settings.
 
+## List SSO Settings
+
+`GET /api/v1/sso-settings`
+
+Lists the SSO Settings for all providers.
+
+**Required permissions**
+
+See note in the [introduction]({{< ref "#sso-settings" >}}) for an explanation.
+
+| Action          | Scope                        |
+| --------------- | ---------------------------- |
+| `settings:read` | `settings:auth.{provider}:*` |
+
+**Example Request**:
+
+```http
+GET /api/v1/sso-settings HTTP/1.1
+Accept: application/json
+Content-Type: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+```
+
+**Example Response**:
+
+```http
+HTTP/1.1 200
+Content-Type: application/json
+[
+  {
+    "id":        "1",
+    "provider":  "github",
+    "settings": {
+      "apiUrl": "https://api.github.com/user",
+      "clientId": "my_github_client",
+      "clientSecret": "*********",
+      "enabled": true,
+      "scopes": "user:email,read:org"
+      // rest of the settings
+    },
+    "source":    "system",
+  },
+  {
+    "id":        "2",
+    "provider":  "azuread",
+    "settings": {
+      "authUrl": "https://login.microsoftonline.com/00000000-0000-0000-0000-000000000000/oauth2/v2.0/authorize",
+      "clientId": "my_azuread_client",
+      "clientSecret": "*********",
+      "enabled": true,
+      "scopes": "openid,email,profile"
+      // rest of the settings
+    },
+    "source":    "system",
+  }
+]
+```
+
+Status Codes:
+
+- **200** – SSO Settings found
+- **400** – Bad Request
+- **401** – Unauthorized
+- **403** – Access Denied
+
 ## Get SSO Settings
 
 `GET /api/v1/sso-settings/:provider`