Mark config keys that are available with wg-quick only

[OJFord]

DNS and Address for example are only valid config items when using the wg-quick tool, IMO it would be good to distinguish these and any others, just a brief:

[wg-quick only]

marker, perhaps linking to a section that explains.

[pirate]

Sure, although I'm surprised anyone uses raw wg tbh, wg-quick has always seemed like the primary user-facing CLI to me.

[OJFord]

Depends on use case I suppose, if you're using it as a client(s) - server VPN for privacy or whatever wg-quick is probably great. For networking many servers though you might prefer to use systemd (supports WireGuard netdevs as of v241 as I recall, better support in 243) or similar file-based config.

[pirate]

I just checked and wg-quick handles a superset of wg's file-based config features. I use it for my server-to-server VPN, not for privacy, and have never felt the need to drop down to raw wg. I remain unconvinced that anyone should start by using wg directly unless they already know what they're doing (in which case they don't need these docs anyway), but I still think labeling them better is harmless so I'll leave this issue open.