Add a reference project for WooCommerce

[t4top]

I see on the README page that you are looking to integrate Solana Pay with WooCommerce. I have a reference implementation that I created for the last Grizzlython Hackathon. Is it fine to raise a PR for it? Do you prefer the PR

• be created as a folder under the examples directory or
• should it just be in the root directory in a separate branch like the Shopify sample or
• should it be just a link in the README.md pointing to my repo?

Below are links to my repo and the demo site showing it in action. Code Repo: https://github.com/aztemi/wc-solana-pay/ Demo Store: https://solana-pay-demo.juxdan.io/