[nginx] Source switched to GitHub

[adriens]

❔ About

I've just seen the news : "NGINX Open Source development repository has moved from Mercurial to GitHub. 🥳"

while the agent is here : https://github.com/nginx/agent/releases/tag/v2.38.0

The official repo is here : https://github.com/nginx/nginx

🎯 The question

How should the product be impacted for :

• Automated releases
• Official documentation link
• purl
• Any other related resource

[captn3m0]

This should also reflect as an update in the identifiers.

[adriens]

Indeed @captn3m0