Update readme for public cli (#251)

packages/cli/README.md

@@ -1,3 +1,41 @@
 # Rate My OpenAPI CLI
 
-This repo contains the public cli
+<p align="center">
+  <a href="https://ratemyopenapi.com/">
+    <img src="https://github.com/zuplo/rate-my-openapi/blob/main/assets/gh-header.png" height="96">
+    <h3 align="center">Rate My Open API</h3>
+  </a>
+</p>
+
+This CLI project aims to give a rating to OpenAPI definitions so you can understand
+how helpful they are for the OpenAPI lifecycle. Having a low score might mean
+that your journey of governing your API is going to be harder than it should.
+
+# RMOA CLI
+
+```
+rmoa <command>
+
+Commands:
+rmoa lint
+
+Uploads an Open API file & gets it's Rate My Open API results
+
+Options:
+  --version   Show version number                                      [boolean]
+  --help      Show help                                                [boolean]
+  --api-key   The API Key from Zuplo                         [string] [required]
+  --filename  The OpenApi file name to process               [string] [required]
+  --dir       The directory containing your Open API file[string] [default: "."]
+  --output    default, json                        [string] [default: "default"]
+```
+
+## Using the CLI
+
+You can also use the CLI to lint & get a score for your OpenAPI definition.
+Create your api key on the [Rate My Open API Portal](https://api.ratemyopenapi.com/docs)
+
+```
+npx rmoa lint --dir /path/to/your/ --filename openapi.json --api-key zpka_1b...
+```
+