[DOCS] Getting Started - Incorrect JDK install links

### Describe the issue

[Getting started guide](https://aws.github.io/aws-pdk/getting_started/index.html) under the `Prerequisites` > `JDK + Maven` section lists https://docs.aws.amazon.com/corretto/ as the link to install Corretto. This link points to the user guide for Corretto and do not provide a download option. A better link to provide here would be https://aws.amazon.com/corretto/ which provides multiple download options.

### Links

https://aws.github.io/aws-pdk/getting_started/index.html

Open the Getting Started guide and navigate to Prerequisites > JDK + Maven. Update the Corretto installation link from the user guide to the AWS Corretto page, then verify that the rendered link provides download options.

Written by the indexing model from the issue text.