Private Network Access is replaced by Local Network Access

[Elchi3]

Specification

https://github.com/WICG/local-network-access

Description

The private-network-access feature seems to be on hold/no longer being worked on. Not sure what this means for us. See https://github.com/WICG/local-network-access and https://developer.chrome.com/blog/pna-on-hold

Documentation

https://developer.chrome.com/blog/local-network-access

Browser support

BCD PR mdn/browser-compat-data#27492

[ddbeck]

With a single implementer, I'd guess that means we could mark the private network access (PNA) feature as discouraged (and pending removal?) and point to a new local network access feature as an alternative. We don't need the second feature to discourage the first, but making both changes together would be nice.