[BUG] Documentation for using the CORS middleware suggests installing JWT middleware

This is a documentation bug - would be happy to open a PR for that, but I can't find the repository where documentation is edited.

On this page:

https://docs.iris-go.com/iris/security/cors#using-the-cors-middleware

Under "Using the CORS middleware", it says:

```
1. Install the middleware:

$ go get github.com/iris-contrib/middleware/jwt@master
```

This should, instead, be

```
go get github.com/iris-contrib/middleware/cors
```