instructions for configuring redocly rules

Author: JaredCE

README.md

@@ -942,16 +942,31 @@ This will set the `Cache-Control` Response Header to have a value of "no-store"
 
 Validation for the OpenAPI Description is now (as of 0.0.90) done by [Redocly](https://redocly.com/). This is a slightly less opinionated validator for an OpenAPI Description, it should result in less errors around "YAML Anchors". It's also a maintained library, and has support for OpenAPI 3.1.0 which I hope to be able to support very soon.
 
+I am making use of https://www.npmjs.com/package/@redocly/openapi-core, which I have been warned is likely to change. If you notice anything going wrong with validation of your OpenAPI Description, feel free to open an issue here. I make active use of this library, so will hopefully come across those issues too.
+
+### Rules
+
 I have configured the validator to use these Rules:
 
-* [spec](https://redocly.com/docs/cli/rules/spec/)
-* [path-parameters-defined](https://redocly.com/docs/cli/rules/path-parameters-defined/)
-* [operation-2xx-response](https://redocly.com/docs/cli/rules/operation-2xx-response/)
-* [operation-4xx-response](https://redocly.com/docs/cli/rules/operation-4xx-response/)
-* [operation-operationId-unique](https://redocly.com/docs/cli/rules/operation-operationid-unique/)
-* [path-declaration-must-exist](https://redocly.com/docs/cli/rules/path-declaration-must-exist/)
+- [spec](https://redocly.com/docs/cli/rules/spec/)
+- [path-parameters-defined](https://redocly.com/docs/cli/rules/path-parameters-defined/)
+- [operation-2xx-response](https://redocly.com/docs/cli/rules/operation-2xx-response/)
+- [operation-4xx-response](https://redocly.com/docs/cli/rules/operation-4xx-response/)
+- [operation-operationId-unique](https://redocly.com/docs/cli/rules/operation-operationid-unique/)
+- [path-declaration-must-exist](https://redocly.com/docs/cli/rules/path-declaration-must-exist/)
 
-I am making use of https://www.npmjs.com/package/@redocly/openapi-core, which I have been warned is likely to change. If you notice anything going wrong with validation of your OpenAPI Description, feel free to open an issue here. I make active use of this library, so will hopefully come across those issues too.
+However, you can configure your own rules from the [ruleset available on the Redocly site](https://redocly.com/docs/cli/rules/built-in-rules/). To do this, you will need to create a `redocly.json` file within an `options` folder. The file should look like:
+
+```json
+{
+  "spec": "error",
+  "path-parameters-defined": "error",
+  "operation-2xx-response": "error",
+  "operation-4xx-response": "error",
+  "operation-operationId-unique": "error",
+  "path-declaration-must-exist": "error"
+}
+```
 
 ## Example configuration