Add mint a11y CLI command (#1448)

* add `mint a11y` command

* copy edit other commands

Author: ethanpalm

installation.mdx

@@ -98,37 +98,43 @@ mint dev --group admin
 
 ## Additional commands
 
-While `mint dev` is the most commonly used command, there are other commands you can use to manage your documentation.
+### Find broken links
 
-### Finding broken links
-
-The CLI can assist with validating reference links made in your documentation. To identify any broken links, use the following command:
+Identify any broken internal links with the following command:
 
 ```bash
 mint broken-links
 ```
 
-### Checking OpenAPI spec
+### Find accessibility issues
+
+Test the color contrast ratios and search for missing alt text on images and videos in your documentation with the following command:
+
+```bash
+mint a11y
+```
+
+### Check OpenAPI spec
 
-You can use the CLI to check your OpenAPI file for errors using the following command:
+Check your OpenAPI file for errors with the following command:
 
 ```bash
-mint openapi-check <openapiFilenameOrUrl>
+mint openapi-check <OpenAPI filename or URL>
 ```
 
-You can pass in a filename (for example, `./openapi.yaml`) or a URL (for example, `https://petstore3.swagger.io/api/v3/openapi.json`).
+Pass a filename (for example, `./openapi.yaml`) or a URL (for example, `https://petstore3.swagger.io/api/v3/openapi.json`).
 
-### Renaming files
+### Rename files
 
-You can rename and update all references to files using the following command:
+Rename and update all references to files with the following command:
 
 ```bash
-mint rename <oldFilename> <newFilename>
+mint rename <path/to/old-filename> <path/to/new-filename>
 ```
 
-### Migrating MDX endpoint pages
+### Migrate MDX endpoint pages
 
-You can migrate MDX endpoint pages to autogenerated pages from your OpenAPI specification using the following command:
+Migrate MDX endpoint pages to autogenerated pages from your OpenAPI specification with the following command:
 
 ```bash
 mint migrate-mdx