[FT-2788]fix opa documents undefined return (#4211)

* [FT-2788]fix opa documents undefined return

* add missing config params

* copy edit + vale

Co-authored-by: angel <angel.guarisma@konghq.com>

app/_hub/kong-inc/opa/_index.md

@@ -79,6 +79,18 @@ params:
       default: false
       description: |
         If set to true, the Kong Gateway Consumer object in use for the current request (if any) is included as input to OPA.
+    - name: include_body_in_opa_input
+      required: false
+      datatype: boolean
+      default: false
+      description: |
+        If set to true, the current requests' request body is included as input to OPA.
+    - name: include_parsed_json_body_in_opa_input
+      required: false
+      datatype: boolean
+      default: false
+      description: |
+        If set to true and the `Content-Type` header of the current request is `application/json`, the request body will be JSON decoded and the decoded struct is included as input to OPA.
 ---
 
 ## Usage
@@ -95,7 +107,9 @@ Create an `example.rego` file with the following content:
 ```rego
 package example
 
-default allow = false
+default allowBoolean = false
+default allowDetailed = false
+
 
 allowBoolean {
   header_present
@@ -140,7 +154,7 @@ curl -XPUT localhost:8181/v1/policies/example --data-binary @example.rego
 The above command uses OPA's default port 8181. It could be different for your
 setup.
 
-### Set up Kong Gateway
+### Set up {{site.base_gateway}}
 
 Set up a Route and Service in {{site.base_gateway}} and then enable the plugin: