docs: Markdownlint fixes

README.md

@@ -12,19 +12,19 @@
 
 ### Node
 
-```
+```sh
 npx @redocly/cli lint path-to-root-file.yaml
 ```
 
 Alternatively, install it globally with `npm`:
 
-```
+```sh
 npm install @redocly/cli -g
 ```
 
 Then you can use it as `redocly [command] [options]`, for example:
 
-```
+```sh
 redocly lint path-to-root-file.yaml
 ```
 
@@ -36,13 +36,13 @@ To give the Docker container access to the OpenAPI description files, you need t
 mount the containing directory as a volume. Assuming the API description is rooted
 in the current working directory, you need the following command:
 
-```
+```sh
 docker run --rm -v $PWD:/spec redocly/cli lint path-to-root-file.yaml
 ```
 
 To build and run with a local image, run the following from the project root:
 
-```
+```sh
 docker build -t redocly/cli .
 docker run --rm -v $PWD:/spec redocly/cli lint path-to-root-file.yaml
 ```
@@ -53,7 +53,7 @@ docker run --rm -v $PWD:/spec redocly/cli lint path-to-root-file.yaml
 
 Redocly CLI is a great way to render API reference documentation. It uses open source [Redoc](https://github.com/redocly/redoc) to build your documentation. Use a command like this:
 
-```
+```sh
 redocly build-docs openapi.yaml
 ```
 
@@ -73,7 +73,7 @@ Our API linter is designed for speed on even large documents, and it's easy to r
 
 Try it like this:
 
-```
+```sh
 redocly lint openapi.yaml
 ```
 

docs/rules/built-in-rules.md

@@ -13,6 +13,10 @@ The _Special rules_ group contains rules that may apply to multiple objects or t
 Build [configurable rules](./configurable-rules.md) if the rule you need isn't listed.
 {% /admonition %}
 
+## List of available rules
+
+Details of all the rules available "out of the box" with Redocly CLI are listed below. Visit each individual page for details of what the rule does, additional configuration options, and examples of it in use.
+
 ### Special rules
 
 - [no-unresolved-refs](./no-unresolved-refs.md): Every `$ref` must exist