thomasgauvin: add explanations to connect to private network db from …#19394

Oxyjun merged 2 commits intoproductioncloudflare/cloudflare-docs:productionfrom

thomasgauvin-hyperdrive-private-db-over-tunnels-detailscloudflare/cloudflare-docs:thomasgauvin-hyperdrive-private-db-over-tunnels-detailsCopy head branch name to clipboard