This changes the default firewall method used by Tailscale to nftables.
The 'autodetection' mode is only supported by arm64 and amd64 for now[1].
This causes mips devices to not do proper detection and incorrectly default back to
iptables.
I added a fw_mode variable to the tailscale.conf file that could be
set to iptables for easy conversion for someone still using iptables.
I was able to test on an older mips device and my current aarch64
without issues.
Also a few readme updates to bring it up to the current status.
1. dc7aa98b76/util/linuxfw/linuxfw_unsupported.go (L4C58-L4C58)
Signed-off-by: Tyler Young <git@yfh.addy.io>
Tyler Young