Where can I find documentation for a specific version

I am using primeng components with version 1.1.1. But on their website ( https://www.primefaces.org/primeng ) I can only find documentation for the latest version. Where can I find documentation for a specific version? I don't want to update to the latest version as I might mess up something in my project. In addition, new versions of components are released quite often. Now with my version I am having trouble developing (getting some errors) as I don't know what features are supported (since I can only link to the latest version on my site).