docs: add query_parameters_to_set

Signed-off-by: Mikhail Sedov <[email protected]>

Author: sedovmik

docs/content/envoy-primer.md

@@ -107,6 +107,7 @@ If you want, you can also control the HTTP status sent to the upstream or downst
 * `body` is a string which represents the response body data sent to the downstream client when a request is denied.
 * `status_code` is a number which represents the HTTP response status code sent to the downstream client when a request is denied.
 * `dynamic_metadata` is an object whose keys are strings and values can be booleans, strings, numbers, arrays, or objects. It will set the `DynamicMetadata` in the `CheckResponse` returned by the `opa-envoy-plugin` and can be consumed elsewhere in the envoy filter chain.
+* `query_parameters_to_set` is an object whose keys are strings and values can be strings or arrays of strings. It defines the query parameters to be added or modified in the request before dispatching it to the upstream when a request is allowed. When a value is an array, it represents multiple values for the same parameter key.
 
 ```live:obj_example:module:openable
 package envoy.authz
@@ -127,6 +128,11 @@ request_headers_to_remove := ["one-auth-header", "another-auth-header"]
 
 response_headers_to_add["x-foo"] := "bar"
 
+query_parameters_to_set = {
+    "user-role": token.payload.role,
+    "tags": ["main-flow", "auth-enabled"]
+}
+
 status_code := 200 if {
 	allow
 } else := 401 if {