docs: adds http api dashboard permissions

docs/sources/http_api/dashboard_permissions.md

++++
+title = "Dashboard Permissions HTTP API "
+description = "Grafana Dashboard Permissions HTTP API"
+keywords = ["grafana", "http", "documentation", "api", "dashboard", "permission", "permissions", "acl"]
+aliases = ["/http_api/dashboardpermissions/"]
+type = "docs"
+[menu.docs]
+name = "Dashboard Permissions"
+parent = "http_api"
++++
+
+# Dashboard Permissions/ACL API
+
+This API can be used to update/get the ACL for a dashboard or a folder.
+
+Permissions with dashboardId set to `-1` are the default permissions for users with the Viewer and Editor roles. Permissions can be set for a user, a team or a role (Viewer or Editor). Permissions cannot be set for Admins - they always have access to everything.
+
+The permission levels for the permission field:
+
+- 1 = View
+- 2 = Edit
+- 4 = Admin
+
+## Get ACL/Permissions for a Dashboard or Folder
+
+`GET /api/dashboards/id/:dashboardId/acl`
+
+Gets all existing dashboard permissions for the dashboard or folder with the given `dashboardId`.
+
+**Example request for getting the ACL/Permissions**:
+
+```http
+GET /api/dashboards/id/1/acl HTTP/1.1
+Accept: application/json
+Content-Type: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+```
+
+**Example Response**
+
+```http
+HTTP/1.1 200 OK
+Content-Type: application/json; charset=UTF-8
+Content-Length: 551
+
+[
+  {
+    "id": 1,
+    "dashboardId": -1,
+    "created": "2017-06-20T02:00:00+02:00",
+    "updated": "2017-06-20T02:00:00+02:00",
+    "userId": 0,
+    "userLogin": "",
+    "userEmail": "",
+    "teamId": 0,
+    "team": "",
+    "role": "Viewer",
+    "permission": 1,
+    "permissionName": "View",
+    "uid": "",
+    "title": "",
+    "slug": "",
+    "isFolder": false,
+    "url": ""
+  },
+  {
+    "id": 2,
+    "dashboardId": -1,
+    "created": "2017-06-20T02:00:00+02:00",
+    "updated": "2017-06-20T02:00:00+02:00",
+    "userId": 0,
+    "userLogin": "",
+    "userEmail": "",
+    "teamId": 0,
+    "team": "",
+    "role": "Editor",
+    "permission": 2,
+    "permissionName": "Edit",
+    "uid": "",
+    "title": "",
+    "slug": "",
+    "isFolder": false,
+    "url": ""
+  }
+]
+```
+
+Status Codes:
+
+- **200** - Ok
+- **403** - Access denied
+- **404** - Dashboard not found
+
+## Save Dashboard Permissions/ACL for a Dashboard or Folder
+
+`POST /api/dashboards/id/:dashboardId/acl`
+
+Updates the ACL for a dashboard or folder. Takes in a list of permissions and adds, remove or updates permissions in the list in the database.
+
+**Example request for saving a list of permission items**:
+
+```http
+POST /api/dashboards/id/1/acl
+Accept: application/json
+Content-Type: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+
+  "items": [
+    {
+      "role": "Viewer",
+      "permission": 1
+    },
+    {
+      "role": "Editor",
+      "permission": 2
+    },
+    {
+      "teamId": 1,
+      "permission": 1
+    },
+    {
+      "userId": 11,
+      "permission": 4
+    }
+  ]
+}
+```
+
+JSON body schema:
+
+- **items** - The permission items to add/update. Items that are omitted from the list will be removed from the db.
+
+**Example response**:
+
+```http
+HTTP/1.1 200 OK
+Content-Type: application/json; charset=UTF-8
+Content-Length: 35
+
+{"message":"Dashboard acl updated"}
+```
+
+Status Codes:
+
+- **200** - Ok
+- **403** - Access denied
+- **404** - Dashboard not found
+
+
+## Delete Permission from the Dashboard ACL/Permissions List for a Dashboard or Folder
+
+`DELETE /api/dashboards/id/:dashboardId/acl/:aclId`
+
+The above will delete an item from a dashboard or folder ACL given the id of the permission item.
+
+**Example Request**:
+
+```http
+DELETE /api/dashboards/id/1/acl/540 HTTP/1.1
+Accept: application/json
+Content-Type: application/json
+Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
+```
+
+**Example Response**:
+
+```http
+HTTP/1.1 200
+Content-Type: application/json
+Content-Length: 0
+```
+
+Status Codes:
+
+- **200** - Ok
+- **403** - Access denied
+- **404** - Dashboard permission not found
+